1. INTRODUCTION In the Easel Paintings ConservationRestoration Studio of The Arts Academy in Split, a number of different materials have been used over the years to reconstruct losses in the paint layer. Usually, a layered system of retouching is employed, consisting of underpainting, isolating varnish, final layers of retouching and final varnish. During the layering process, special care is taken to ensure that the medium does not resolubilise the lower layer or layers. Whether it will be possible selectively to remove the added layers in the future is rarely taken into consideration. It would be highly beneficial if one could, for example, remove the final varnish without disturbing the final layers of retouching, or remove the final layers of retouching without damaging the isolating varnish. As a part of Dorotea Krstić’s master’s thesis, in 2016 a project was initiated that aims to: 1) create a chart enabling the easy Keywords Selective removal; Underpainting; Isolating Varnish; Retouching; Final Varnish comparison of the solubility (and compatibility) of different materials used in the layered system of retouching, and 2) design layered systems of retouching for oil paintings that enable selective removal of their constituents. This article focuses on the first phase of the project: the analysis of the materials used in the Easel Paintings ConservationRestoration Studio of The Arts Academy in Split, and a critical evaluation of the possibility of their selective removal with the use of pure solvents. In the following phase a bibliographic study will be conducted of the materials generally used in layered systems of retouching. The possibility of their selective removal with solvents will also be evaluated. In the last stage of the project, layered systems of retouching will be proposed in which layers can be selectively removed from the top down. 2. METHODOLOGY In order to determine if layered systems of retouching used in The Arts Academy’s Easel Paintings Conservation-Restoration Studio can be removed selectively, the first step was to identify the materials that were used. The information was collected from the printed documentation stored in the Studio’s archive, which encompassed the period from 2002 to 2017. It should be noted that all the paintings included in this survey were done in oil. The data were presented in the form of a table providing information about the artwork (artist’s name, title, date of creation, owner/location) and the materials used for each of the layers in the system: underpainting, isolating varnish, retouching and final varnish (see Table 1). The data were sorted in chronological order, starting with the first painting treated in the Studio (the treatment was completed in 2002) and ending with a painting whose treatment has been completed very recently (in 2017). This enabled the use of different materials to be tracked and certain trends to be established.
202 Sagita Mirjam Sunara | Dorotea Krstić The next step was to present chronologically the use of specific materials for each of the four layers: underpainting, isolating varnish, retouching, and final varnish. For each layer, a table was created that includes the following information: material, comments (for example, the concentration of a varnish solution), the year in which the treatment was completed and general information about the artwork. The final step was critically to evaluate the possibility of selective removal of individual layers in the systems used. First, the data on the solubility of the resins used for the preparation of varnish and of the materials used as paint binders were collected from the existing literature. [1–5] Not all of the sources provide information on sample preparation [4], but those that do indicate that solubility testing was performed on freshly prepared samples. Only Horie gives information on solubility of aged dammar and mastic. [3] No practical tests have been carried out as a part of our research. For easier comparison, the data collected from the literature were presented in tables. Next, the solubility of the materials in each of the layered systems used was compared. For ease of reference, tables were used to present the data. 3. RESULTS Underpainting. The types of paint used were watercolour, gouache, Table 1• An example of a layered system used in the Arts Academy’s Easel Paintings Conservation-Restoration Studio GENERAL INFORMATION ABOUT THE ARTWORK UNDER-PAINTING ISOLATING VARNISH RETOUCHING FINAL VARNISH Anonymous Venetian painter, Flagellation of Christ, 17th century, Parish house of Holy Cross Church, Split Acrylic paint 16 % solution of dammar in turpen tine Pigments bound with Canada balsam 10 % solution of Paraloid B72 in toluene Table 2 • Solubility of the materials used in the layered system of retouching No. 1 DMSO DIACETONE ALCOHOL BUTAN-1-OL PROPAN-2-OL ETHANOL ETHYL ACETATE ACETONE XYLENE TOLUENE SPIRIT OF TURPENTINE WHITE SPIRIT Final varnish: Dammar Retouching: Canada balsam Isolating varnish: Paraloid B72 – Insoluble – Soluble – Borderline or partially soluble
Selective removal of layers in layered systems of retouching: a research project in progress 203 tempera and acrylic. The most commonly used material was watercolour: it was used on 16 out of 26 paintings. Isolating varnish. Paraloid B72 and dammar resin were used for the preparation of an isolating varnish. Dammar varnish was used on 11 out of 21 paintings. Paraloid B72 varnish was used in the remaining 10 cases. Final retouching. Several types of paint were used for final retouching, usually prepared in the Studio by the mixing of pigments with a selected binder. Canada balsam, Paraloid B72 and MS2A were used as binder materials. Occasionally, premixed paints were used: Maimeri Restoration Colors (binder: mastic resin) and watercolour (binder: gum arabic). The most commonly used materials for retouching were paints Table 3 • Solubility of the materials used in the layered system of retouching No. 2 DMSO DIACETONE ALCOHOL BUTAN-1-OL PROPAN-2-OL ETHANOL ETHYL ACETATE ACETONE XYLENE TOLUENE SPIRIT OF TURPENTINE WHITE SPIRIT Final varnish: Paraloid B72 Retouching: Mastic Isolating varnish: Dammar – Insoluble – Soluble – Borderline or partially soluble Table 4 • Solubility of the materials used in the layered system of retouching No. 3 DMSO DIACETONE ALCOHOL BUTAN-1-OL PROPAN-2-OL ETHANOL ETHYL ACETATE ACETONE XYLENE TOLUENE SPIRIT OF TURPENTINE WHITE SPIRIT Final varnish: Paraloid B72 Retouching: Canada balsam Isolating varnish: Dammar – Insoluble – Soluble – Borderline or partially soluble prepared with the use of Canada balsam as binder. That paint was used on 17 out of 24 paintings. Pigments bound with Paraloid B72 were used for the retouching of four paintings. In the other three cases, Maimeri Restoration Colors, watercolour and MS2A-bound paint were used. Final varnish. Paraloid B72, dammar and Regalrez 1094 were used for the final varnishing. Paraloid B72 was used
204 Sagita Mirjam Sunara | Dorotea Krstić Table 7 • Solubility of the materials used in the layered system of retouching No. 6 DMSO DIACETONE ALCOHOL BUTAN-1-OL PROPAN-2-OL ETHANOL ETHYL ACETATE ACETONE XYLENE TOLUENE SPIRIT OF TURPENTINE WHITE SPIRIT Final varnish: Regalrez 1094 Retouching: MS2A Isolating varnish: Dammar – Insoluble – Soluble – Borderline or partially soluble Table 5 • Solubility of the materials used in the layered system of retouching No. 4 DMSO DIACETONE ALCOHOL BUTAN-1-OL PROPAN-2-OL ETHANOL ETHYL ACETATE ACETONE XYLENE TOLUENE SPIRIT OF TURPENTINE WHITE SPIRIT Final varnish: Paraloid B72 Retouching: Canada balsam Isolating varnish: Paraloid B72 – Insoluble – Soluble – Borderline or partially soluble Table 6 • Solubility of the materials used in the layered system of retouching No. 5 DMSO DIACETONE ALCOHOL BUTAN-1-OL PROPAN-2-OL ETHANOL ETHYL ACETATE ACETONE XYLENE TOLUENE SPIRIT OF TURPENTINE WHITE SPIRIT Final varnish: Dammar Retouching: Canada balsam Isolating varnish: Dammar – Insoluble – Soluble – Borderline or partially soluble
Selective removal of layers in layered systems of retouching: a research project in progress 205 in 15 of 19 cases. Dammar varnish was used on three paintings, while Regalrez 1094 was used only once. Our research revealed that six layered systems of retouching were employed. Solubility of the materials used is presented in Tables 2 – 7. Information on materials used in underpainting has not been included because solubility properties of underpainting and isolating varnish generally differ (acrylic paint presents an exception). It should be noted that in several cases final varnish was not applied. Such systems are not presented separately because their constituents match those presented in the tables shown on previous pages. 3. CONCLUSIONS The information collected allowed conclusions to be made as to whether the systems that have been used so far enable the selective removal of individual layers. The data indicate that selective removal of layers is possible in only one of the six systems used (system No. 3). In three systems one might at best be able to remove the varnish and retouching without damaging the isolating varnish (system No. 1, 2 and 6). The next step of the research is critically to evaluate the systems described in professional literature, and to propose reversible layered system(s) of retouching for oil paintings, either new or those already in use. Further research should focus on finding a system – or a method of application – that meets specific aesthetic requirements (saturation, gloss etc.). REFERENCES [1] DALE SMITH, Gregory; JOHNSON, Ronald – Strip ‘Teas’ – solubility data for the removal (and application) of low molecular weight synthetic resins used as inpainting media and picture varnishes, Western Association of Art Conservation Newsletter, Vol. 30, n.º 1 (2008), pp. 11–19. [2] GETTENS, Rutherford John; STOUT, George Leslie – Painting Materials : A Short Encyclopedia, New York: Dover Publications, 1966. [3] HORIE, Charles Velson – Materials for Conservation : Organic Consolidants, Adhesives and Coatings, London; Boston: ButterworthHeinemann, 1987. [4] KREMER Pigmente website – Canada Balsam. Available at: http://shop. kremerpigments.com/media/pdf/62110e.pdf [5 December 2015]. [5] WHITTEN, Jill; MENTION, Elisabeth; Merz-Lê, Liisa; Barach Cox, Ruth; Fisher, Sarah L.; McGinn, Mary; Proctor, Robert; Van Vooren, Camilla; Swicklik, Michael; Berger, Mira & Gustav – Low Molecular Weight Varnishes (1997). AIC Wiki website. Available at: http:// www.conservation-wiki.com/wiki/IV._Low_ Molecular_Weight_Varnishes [5 December 2015].
Abstract Among several of survived painted portraits from Pompeii there is one small but famous painting known as the Sappho - Girl with Stylus and Tablets - most likely created around 50 AD and found in the house of the Insula Occidentalis. This work is related to the reconstruction of Sappho and it aims to investigate the Classical Roman painting techniques and working methods. Historically informed materials were used in the process but with a modern modification - a XSP was placed as a support, instead of the wall. It is hoped that this study will enable a better understanding of fresco painting techniques, thus facilitating working methods for future retouching projects. RECONSTRUCTING OF THE SAPPHO PAINTING TOWARDS A BETTER UNDERSTANDING IN RETOUCHING Marija Lena Bošković (1) | Sandra Šustić (2) 1. Arts Academy of the University of Split (graduate student), Zagrebacka 3, 21000 Split - Croatia; [email protected] 2. Arts Academy of the University of Split, Zagrebacka 3, 21000 Split - Croatia; [email protected]
1. INTRODUCTION The Pompeian medallion portrait known as the “Sappho”, now in Naples Archaeological Museum, is one of the most precious paintings of the Italian cultural heritage. This is essentially related to the eruption of Mt. Vesuvius that destroyed the Pompeii in 79 A.D. The excellent preservation state of the ruins allowed the investigators to examine the original fresco techniques directly on the ancient Pompeian yard, where the lava flow saved the frescoes from loss. [1] Based on the published research results and historical sources, a reconstruction of the Sappho has been made. The primary intention of this practice was to analyse the Classical Roman painting techniques and working methods. Correspondingly, this project also enabled to practice skill development necessary for future work in retouching. With accordance to the educational purpose of this project, the stratigraphy of the painting was left exposed in Keywords Sappho Fresco Painting reconstruction Ancient pigments Roman art several cutaway sections, in order to observe the textures, the transparencies and the brush strokes at every stage of the reconstruction process. 2. MATERIALS AND METHODS Since no accessible information were found about the original type of the plaster or pigments applied on Sappho, the traditional Roman lime plaster recipe as well as the pigment palate available in Roman period were used as a reference. Where traditional pigments were hard to obtain, due to their toxicity and/or price on the market, contemporary substitutions were applied (table 1). [1] According to historical sources [2] and published technical studies [1,3], the paintings of this period were made in buon fresco, where pigments, due to the carbonation of lime, form a permanent bond with the plaster. Unlike the original approach, the reconstruction featured both buon fresco and fresco secco methods. Those methods gave an interesting insight into the application methods of the same paint on a different kind of ground. 2.1. RECONSTRUCTION OF THE PREPARATORY LAYERS Although originally a wall painting, the reconstruction was prepared on a Table 1 • Pigments used in reconstruction of the paint layer
208 Marija Lena Bošković | Sandra Šustić portable fresco panel made from XSP. With the aim to achieve optimal plaster adherence, the surface of XSP was evenly scratched. The roughcast was made of lime and white sand particles of 3-4 mm in the 1 to 1 ratio with addition of water, and spread over the surface. The layer was less than 2 cm thick, and of a volume of cca 1,2 L. Decision not to apply the second layer of the plaster was made. This was to prevent the fracture of the painting caused by the excess weight. The preparatory sketch, imitating sinopia, was carried out with charcoal and umber. Next, the intonaco, a coat 5 mm thick was applied after ariccio was almost completely dry. It was made of fine sand from the town Turjak in Croatia with size of the particles less than 2 mm. The sand was mixed with lime in ratio 2:1,5, making its volume around 6,7 dL. Since Sappho is rather small painting, the decision was made to cover the whole surface with this layer which is opposed to the traditional practice in which the intonaco is applied exclusively to those areas which are expected to be painted in a single session (giornata). Consequently, the sketch of sinopia couldn’t be used as a guideline, so it had to be repeated. The spolvero technique was used for this purpose, while the composition was traced with umber pigment mixed with lime water as binder (Figure 1). The same paint was used in underpainting. 2.2. RECONSTRUCTION OF THE PAINT LAYER The reconstruction of the paint layer was initiated while the plaster was still moist. Due to the process of carbonization, the paint formed a firm bond with the plaster. Slowly and precisely the chiaroscuro was build using a soft brush. The transparency of paint was adjusted by varying the amount of lime water. After the plaster was completely dry the painting process was continued with fresco secco technique which required much more attention: it was necessary to apply only the thick paint with brush strokes, otherwise the brush would erase the paint beneath. It is important to emphasize that the application of azurite in the sky area resulted in blackening caused by chemical alterations (Figure 2). Accordingly, it was necessary to repaint this layer with another one that has excluded azurite (Figure 3). The last step in the reconstruction process was to paint the highlights which are present on the hair ornaments, the curls, and the drapery. They were painted when the surface was entirely dried. Sharp edges were Figure 1 • Sinopia Figure 2 • Sappho after buon fresco method (note the blackening of azurite). Figure 3 • Applying Fresco Secco method
Reconstructing of the Sappho painting towards abetter understanding in retouching 209 softened where needed with the semi-dry and clean brush (Figure 4). 3. RESULTS AND DISCUSSION This reconstruction demonstrates that achieving a perfect ratio between the lime water and sand during the plaster preparation may not be a straightforward task - the formation of the small drying cracks can be a common incidence. The most interesting part of this process was to observe how the paint behaves on slightly wet intonaco – the appearance of the brush strokes was extremely light and smooth tonal transitions were easily achieved. While applying various pigments on a wet alkaline environment, a special attention needs to be given to the consequent pigment reactions; azurite, used in the mixture for painting the sky area, started to tarnish after the paint dried, resulting in overall discoloration. Namely due to the presence of alkaline conditions, azurite has transformed to copper oxide (tenorite: CuO).[4] The transparent and smooth brush strokes, easily achieved in buon fresco technique, were replaced with the thick ones during fresco secco. The application of transparent paint layers turned out to be very destructive for the dried paint beneath - the color would become partially smudged or erased. Thus it was necessary to restrict the amount of lime water and match the necessary tone in only one brush stroke. 4. CONCLUSION This reconstruction gave an interesting insight into the working process of Classical Roman painting techniques and working methods. The primary intention of this project was to observe how a pigment behaves in lime water as binder and how the degree of dryness of the plaster effects the working properties and the final appearance of the paint layer. The use of azurite demonstrated the importance of understanding of the paint components which is essential for any reconstruction and retouching to work well. This requires a great deal of study of the paint structure to find out the pigments and binding media present. It is hoped that this study will Figure 4 • Reconstruction of the Sappho painting
210 Marija Lena Bošković | Sandra Šustić enable a better understanding of fresco painting techniques, thus facilitating working methods for future retouching projects. REFERENCES [1] DURAN, A. et.al. - Determination of pigments and binders in Pompeian wall paintings using synchrotron radiation – highresolution X-ray powder diffraction and conventional spectroscopy – chromatography. Archaeometry Vol. 52, n.º 2 (2010), pp. 286– 307. [2] Vitruvius, in Morgan, M. H. (ed. - De architectura libri decem, II (materials) and VII (finishes and colours), Kessinger Publishing, Whitefish, 2005. [3] ALIATIS, Irene et.al. - Pigments used un Roman wall paintings in the Vesuvian area. Journal of Raman Spectroscopy, Vol. 41, (2010), pp. 1537-1542. [4] MATTEI, E. - Raman spectroscopic analysis of azurite blackening, Journal of Raman Spectroscopy, Vol. 39 (2008), pp. 302–306. [5] Natural Pigments. Official website of an art supplier Natural Pigments. Available at: http://www.naturalpigments.com/art-supplyeducation/history-technique-fresco-painting/ [17 April 2016]. [6] Decoded past. Website of the use of colours in Roman frescos. Available at: http:// decodedpast.com/use-colours-brave-showmake-pigments-roman-frescos/13271 [17 April 2016]. [7] Sappho from Pompeii. Website with the data of the Sappho painting. Available at: https://www.awesomestories.com/asset/view/ girl-with-stylus-and-tablets-sappho-frompompeii [17 April 2016]
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Abstract Mario Agrifoglio’s black-light paintings raise specific issues in case of colour reintegration. Metamerism is central in the works made by the artist since the 1970s: according to the type of light source, the perception of colours of his geometric-abstract paintings changes considerably. The identification of materials and techniques used becomes fundamental to define how to retouch Agrifoglio’s paintings without altering their appearance, neither under visible light nor under UV light. To characterise fluorescent THE ISSUE OF METAMERISM IN MARIO AGRIFOGLIO’S PAINTINGS. IDENTIFICATION OF FLUORESCENT PIGMENTS THROUGH RAMAN SPECTROSCOPY TO DEFINE A METHODOLOGY FOR RETOUCHING. Serena Francone (1) | Silvia Bruni (2) | Chiara Zaffino (2) | Katia Galli (2) | Vittoria Guglielmi (2) | Maddalena Boscacci (2) 1 Freelance Conservator of Contemporary Art; viale Kennedy 2, Bregnano (Como, Italy); E-mail address: [email protected] 2 Department of Chemistry, Università degli Studi di Milano; via C. Golgi 19, Milan (Italy); E-mail address: [email protected]
1. INTRODUCTION 1.1 Mario Agrifoglio’s black-light paintings The Italian artist Mario Agrifoglio (1935-2014) was one of the first to systematically use fluorescent paints in the creation of his artworks. He started painting very young, developing an interest in techniques that focused on the exploration of light and colours. After discovering Wood’s lamp during a collaboration for a work of restoration, in the early 1970s Agrifoglio started creating new paintings with a geometric-abstract style using fluorescent colours. The paintings were made in a dark room with a super-fine control of mixtures and overlapping materials pigments used by the artist with precision, Raman Spectroscopy, both normal and surface-enhanced (SERS), was used. Analyses were performed on samples of old vinyl paints taken from three containers found in Agrifoglio’s studio. Raman spectra were then compared to those obtained by the analyses made on samples of new paints of the same brand used by the artist. The results showed a significant similarity between the old and the new paints. Moreover, it was possible to identify the main components responsible for the colour in each paint, in particular copper phthalocyanines for blue and green and rhodamines for red and orange. Keywords Black-light paintings; Colour reintegration; Fluorescent pigments; Metamerism; Non-invasive analyses; Raman spectroscopy. with different fluorescent properties. Thereby, Agrifoglio was able to achieve a completely unexpected aesthetic effect that was variable under both visible and UV light. His paintings question the common understanding of additive and subtractive synthesis and deepen the phenomenon of metamerism, which becomes the protagonist of his art. 1.2 Conservation Issues As Cesare Brandi wrote in his “Theory of restoration” [1], lacuna treatments are primarily a theoretical problem. Retouching should be recognisable to respect the authenticity of the artwork and also to maintain a distance between the time of painting creation and the present in which conservation work occurs. Thus, we should always recognise the aesthetic conservation treatments on a perceptual level. This is possible thanks to a technical differentiation (e.g. rigatino and chromatic selection) and also in the case of mimetic retouching, in which the intervention is visible under UV light. But in the retouching of Agrifoglio’s paintings, metamerism mistakes would compromise the aesthetic message both under visible light and UV light. Thus, to maintain the same appearance in the retouched areas, we must use the same pigments of the original paint layers. Consequently, a new methodology for retouching, which shift the recognisability of the treatment to a different level from the perceptual one, should be defined. 1.3 Aims Fiber Optic Spectroscopy both in Reflection (FORS) and in emission and XRF spectroscopy were already performed on the artist’s paintings
214 Serena Francone | Silvia Bruni | Chiara Zaffino | Katia Galli | Vittoria Guglielmi | Maddalena Boscacci ([2], [3], [4]) but were not enough to characterise the fluorescent pigments. To achieve this goal, it was decided to perform Raman spectroscopy on samples of fluorescent paints, as previous research in scientific literature pointed it out as a technique able to identify the nature of fluorescent organic pigments ([5], [6]). The main materials used by Agrifoglio as fluorescent colours are “Flashe Fluo” vinyl paints by LeFranc & Bourgeois. Fluorescent pigments are fluorescent dyes dissolved in a carrier resin and ground into a fine powder. Fluorescent dyes are dissolved in the carrier resin at a rate of 1-4%, but their chemical compositions are usually not published in order to maintain trade secret protection. The low amount of dyes in paints constitutes the greatest obstacle for their identification. The use of Raman spectroscopy had as objectives: check differences in the composition between old samples of “Flashe Fluo” vinyl paint found in the artist’s studio and the new ones instead of characterise the chemical composition of each of the eight fluorescent colours sold by the brand. 2. MATERIALS AND METHODS Samples of old “Flashe Fluo” paints (red 376, blue 029 and white 001) were taken from three containers dating back to the 1990s, found in the artist’s studio. They were painted on an industrially prepared canvas panel, near samples of new “Flashe Fluo” paints of the same hues. Other samples of all the eight colours of new “Flashe Fluo” (Figure 1) were painted on another canvas panel. The analytical methods used in the present work were Raman and SurfaceEnhanced Raman (SERS) spectroscopy. Raman spectra were acquired by a Jasco RMP-100 microprobe (50x objective) connected by fibre optics with two laser sources (l = 532 and 785 nm) and with an Oriel MS125 spectrometer equipped with an Andor CCD detector. FT-Raman spectra were recorded by a Jasco RFT-600 spectrometer (l = 1064 nm). For SERS measurements a silver colloid prepared according to the Lee-Meisel procedure was employed. Further analyses were performed by combining a separation technique like Thin Layer Chromatography (TLC) and Figure 1 • The eight colours of new “Flashe Fluo” by Lefranc & Bourgeois, analysed and compared with the old ones from the 1990s. Figure 2 • Comparison between FT-Raman or FT-SERS spectra acquired on samples of three hues of old “Flashe Fluo” paints and the new ones.
215 The issue of metamerism in Mario Agrifoglio’s paintings. Identification of fluorescent pigments through raman spectroscopy to define a methodology for retouching. FT-Raman spectra (�exc=1064 nm) White B001 Optical brightener BASF Tinopal OB * * * * * * Bands due to resin FT-Raman spectra (�exc=1064 nm) White B001 Optical brightener BASF Tinopal OB * * * * * * Bands due to resin Figure 3 • The FT-Raman spectrum allowed the identification of the optical brightener constituting White 001. The bands of the brightener are observed together with those of the melamineformaldehyde p-toulensulfonamide resin contained in the pigment. Table 1 • Dyes identified in “Flashe Fluo” paints DYES IDENTIFIED THROUGH TLC-SERS BRIGHTENERS Red 371 Rhodamine B, Rhodamine 6G, Solvent Yellow 160:1 Red 376 Rhodamine B, Rhodamine 6G, Solvent Yellow 160:1 Red 435 Rhodamine B, Rhodamine 6G X Orange 232 Rhodamine B, Rhodamine 6G, Solvent Yellow 160:1 Yellow 173 Solvent Yellow 160:1 X Green 590 Phthalocyanine green PG7, Solvent Yellow 160:1 Blue 029 Phthalocyanine blue PB15 X White 001 - X SERS. TLC separations were executed on silica plates with aluminium support and a mixture of 2-propanol-acetoneammonia 22:1:2 as eluent. 3. RESULTS AND DISCUSSION Analyses carried out on old samples of “Flashe Fluo” paints showed no difference in composition compared to the new ones (Figure 2). Raman and SERS analyses on the samples of the new “Flashe Fluo” paints highlighted the presence of a polyvinyl acetate binder (as confirmed by the IR spectrum). Pigments contained in the paints are composed of a melamine-formaldehyde p-toluenesulfonamide resin (Figure 3) in which are dissolved one or more dyes in different proportion. Also, brighteners and non-fluorescent organic pigments can be found in some colours. The identification of these dyes was done through SERS after TLC separations, thanks to the comparison with reference materials. The main dyes identified for each colour are reported in Table 1. Different colours are the result of different mixtures of dyes. For example, Red 371 and Red 376 are different for a lower content of Solvent Yellow 160:1 in Red 376. Reds and orange are characterised by the presence of rhodamines B and 6G, while in blue and green there are copper phthalocyanines, that are not fluorescent, but they are put together with brighteners or fluorescent dyes (Figure 4). In case of Blue 029 and White 001, brighteners act as fluorescent pigments. Figure 4 • TLC analysis (observed at 365 nm) of Blue 029 in comparison with some commercial optical brighteners. Blue 029 is the last on the right.
216 Serena Francone | Silvia Bruni | Chiara Zaffino | Katia Galli | Vittoria Guglielmi | Maddalena Boscacci 4. CONCLUSIONS The analyses carried out allowed to recognise the organic dyes contained in each fluorescent colour of “Flashe Fluo” vinyl paints by Lefranc & Bourgeois. The comparison between the old samples of paints and the new ones showed that the same components were kept by the brand during time. Fluorescent pigments are produced especially by Chinese and Indian companies and then bought by fine art manufacturers, which add them to specific binders. In this research, it is very important to know which dyes are contained in pigments, as only the same mixtures give the same fluorescence. The painting technique of Agrifoglio is very sophisticated and is based on an in-depth study of aesthetic effects obtained through overlapping of fluorescent paints and non-fluorescent paints. So next steps of research will be focused, on one hand, on the study of the chromatic effects obtained through the layering of different paints, and on the other, on the selection of a binder for retouching with different chemical and physical properties than the original paint layers. In this manner, recognisability will move from a perceptual level to a chemical/physical one. REFERENCES [1] BRANDI, Cesare – Theory of restoration, Torino: Einaudi, 1977, pp. 71-76. [2] FRANCONE, Serena; GARGANO, Marco; BONIZZONI, Letizia; LUDWIG, Nicola – Fluorescent paint by Mario Agrifoglio. Study of the technique and material characterization through non-invasive analyses. In SELVA BONINO, V. Emanuela, Dall’olio all’acrilico, dall’Impressionismo all’arte contemporanea, proceedings of the VII International Congress “Colore & Conservazione” organized by Cesmar7, Politecnico of Milan, 13-14 November 2015. Il Prato, 2016, pp. 272-273. [3] FRANCONE, Serena; GARGANO, Marco; BONIZZONI, Letizia; CERAMI, Lorenzo; LUDWIG, Nicola – A red of all colours: analyses of the painting technique by Mario Agrifoglio and considerations on the retouching of the black-light paintings (in Italian). Proceedings of the XIV National Congress IGIIC “Lo Stato dell’Arte”, Academy of Fine Arts of L’Aquila, 20-22 October 2016. Nardini, 2016, pp. 443-449. [4] FRANCONE, Serena; GARGANO, Marco; BONIZZONI, Letizia; CERAMI, Lorenzo; LUDWIG, Nicola – Mario Agrifoglio’s Convergenze. Conservation issues of blacklight paintings. ICAR journal no.1, Academy of Fine Arts of Warsaw, Poland, 2017, pp. 98-109. [5] COLOMBINI, Alain; KAIFAS, Delphine – Characterization of some orange and yellow organic and fluorescent pigments by Raman spectroscopy, IRUG08 conference, Vienna, 2008. [6] FREMOUT, Wim; SAVERWYNS, Steven – Characterization of daylight fluorescent pigments in contemporary artists’ paints by Raman spectroscopy, IRUG11 conference, Boston, 2014.
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Abstract The authors present case studies in which a complete reconstruction of the missing and damaged parts of the polychromy of three 18th century paintings was carried out. This approach was chosen because of the paintings being displayed in churches where they were the objects of daily veneration. The complete reconstruction of the missing and damaged parts of the polychromy was based on a comparison with the preserved parts of the paintings and in one case on archival photos taken prior to the damage. In all three cases, mastic based Maimeri® restoration colours were used for the retouching. Different retouching techniques (pointillism, tratteggio or a combination of various graphic forms) were used to blend the reconstructed areas with the surrounding original. The authors empirically analysed the gloss of the retouched areas, depending on the type of underlying isolating varnish (dammar RETOUCHING RELIGIOUS PAINTINGS – EXAMPLES FROM PRIVATE PRACTICE Lana Kekez (1) | Kristina Krivec (2) | Julija Baćak (3) 1. Freelance conservator, A. B. Šimića 32, 21000 Split - Croatia; [email protected] 2. Freelance conservator, Put Brda 27, 21000 Split - Croatia; [email protected] 3. Freelance conservator, Kukuljevićeva 10, 21000 Split - Croatia; [email protected]
1. INTRODUCTION The conservation treatment of paintings that are displayed in churches and are a subject of veneration usually requires a complete reconstruction of the missing parts of the polychromy. The conference poster presented three examples of conservation treatments performed on 18th century easel paintings with different types of damage and loss to their polychromy. The decisions on the conservation or Paraloid™ B72). As expected, the colours were semi-glossy to matt in appearance. The gloss of the retouching colours matched that of the Paraloid™ B72 varnish, excluding the need for additional medium. In cases where dammar was used as an isolating varnish it was necessary to add some extra dammar solution to the retouching colours, especially in the darker areas of the polychromy. Keywords Religious paintings; Archival photos; Complete polychromy reconstruction; Maimeri® restoration colours; Gloss of retouching colours; Retouching techniques. treatment and materials were based on the condition of the paintings and the study of the available archival documents as well as the authors’ experience in the field. Decisions regarding reconstruction of the missing parts of the polychromy were thoroughly discussed with the owners and the representatives of the conservation treatment funding program (art historians) [1]. The aim of analysing these three examples was: 1) to compare the sources on which the polychromy reconstructions were based, 2) to study the gloss of the mastic-based Maimeri® restoration colours[2] for retouching when applied on top of two different isolating varnish layers (Paraloid™ B72 and dammar), and 3) to understand which retouching techniques are most suitable to match the texture of the original polychromy, blending the reconstructed areas with the surrounding original in each case. 2. ‘SAINT JOHN THE BAPTIST’ The 18th century altar painting on wood, representing Saint John the Baptist, belongs to the old parish church of Saint Anthony of Padua in Figure 1 • The ‘Saint John the Baptist’ painting before and after the treatment
220 Lana Kekez | Kristina Krivec | Julija Baćak Svib (Croatia), a little village in the Dalmatian hinterland, and is a part of the main altar ensemble together with a similar painting of Saint Michael. Both paintings were overpainted at some point. The original compositions showed the scene of the Annunciation: the Angel Gabriel was painted on what is now the ‘Saint John’ painting and the Virgin was painted on what is now the ‘Saint Michael’ painting. The original paint layer was applied directly to the wood surface, without any ground layer. It was later overpainted with the existing paint layer showing Saint John and Saint Michael, and varnished. The ‘Saint John the Baptist’ painting was severely damaged by candle flame. The whole lower right part of the image was destroyed, including Saint John’s leg, cross and background (Fig. 1). Several examination methods were performed such as the stratigraphic analysis of the polychromy and X-ray radiography. Solubility tests of the varnish and the overpaints were carried out. The conservation treatment included consolidation, cleaning and reconstruction of both wood and polychromy. The burned and missing wood was reconstructed using lime wood strips. It was necessary to apply a filling to the reconstructed wood surfaces to match the height and texture of the surrounding area. Plextol® B500 and Tylose® MH300 based filling was toned to match the original wood. The retouching process demanded a complete reconstruction of the missing parts. Since there was no photo documentation showing the painting prior to the burning, the reconstruction was done by analogy with the preserved parts of the polychromy. In the underpainting only the basic shape and position of the leg, shoe laces and cross were defined. All the details and the background were reconstructed in the final retouching. Since the painting style was quite naive, Saint John’s right leg was symmetrically transferred, using a transparent foil. Saint Michael’s legs, posed in a similar manner, served as a model. Considering the characteristics of the original polychromy (light and relatively matte) and reversibility questions, 15% Paraloid™ B72 in toluene was applied as an isolating varnish layer. On top of it, retouching was done using Maimeri® restoration colours which perfectly matched the varnish gloss level without adding any extra medium. The tratteggio technique allowed satisfactory blending of the reconstructed areas with the surrounding original, leaving them minimally recognizable at the same time (Fig. 1). 3. ‘VIRGIN MARY AND CHILD’ The 18th century altar painting on canvas, depicting Virgin Mary and Child, is kept in the niche of the main stone altar of the cemetery church of Saint Anne in Šibenik (Croatia). The painting was found loosely fixed to an improvised wooden backing and subsequently placed in a wooden box which was completely degraded by moisture and microorganisms. A redtoned ground layer had been applied to the surface of the sparsely woven canvas. The adhesion between the polychromy and the canvas was only locally weakened. Losses to the paint layer mostly corresponded to the damaged areas in the canvas (Fig. 2). Figure 3 • Archival photo, October 1987 and the polychromy reconsFigure 2 • T
struction based on the archival photo Retouching relegious paintings – examples from private practice 221 High humidity in the stone altar niche penetrating into the painting, and the high moisture sensitivity of the canvas had led to its degradation and to a significant loss of the canvas and the polychromy, especially in the area of the Virgin’s nose. Old black and white photos taken in October 1987 were found in the Photo Archive of the Split Conservation Department of the Ministry of Culture [3]. They show the painting prior to its degradation The ‘Virgin Mary and Child’ before conservation Figure 4 • The ‘Virgin Mary and Child’ painting after the treatment
222 Lana Kekez | Kristina Krivec | Julija Baćak and also help dating the damage to somewhere in the last thirty years (Fig. 3). After the stabilization of the support and the polychromy, and the cleaning of the surface, the painting was lined with a dimensionally stable synthetic canvas using Beva 371. The losses in the ground layer were reconstructed using Plextol® B500 and Tylose® MH300 based filling. The retouching was based on the archival photos and on the stylistic characteristics of the painting. The obvious similarity in the shape of the Virgin’s and the Child’s faces was very helpful in the reconstruction of the Virgin’s nose, both in form and in colour (Fig. 3). An underpaint Maimeri® gouache-tempera [4] layer was used only to define the main forms and shadows. Varnish tests showed that dammar will give a satisfactory level of saturation and intensification of the original polychromy, especially in the darker areas. The painting was varnished with 20% dammar in double rectified turpentine with the addition of 2% Tinuvin 292. Maimeri® restoration colours, used for the final retouching, perfectly matched the varnish gloss level without adding any extra medium. The only exception was the dark zone of the Virgin’s blue mantle where it was necessary to add a dammar varnish solution to the retouching colours. To match the texture of the original paint layer and to blend the reconstructed areas with the surrounding original, pointillism retouching was applied in the flesh tones (Fig. 3) and the background. The draperies were retouched using a combination of tratteggio and pointillism (Fig. 4). To protect the painting from humidity within the stone niche, a new wooden box with a protective backing was introduced. 4. ‘THE DEAD CHRIST’ The 18th century oil on canvas representing the Dead Christ comes from the Saint Nicholas church in Šibenik. The painting was found in a poor state of preservation, showing many deformations and losses in both the canvas and the polychromy, most of which caused by poor microclimate conditions and handling. The polychromy was severely damaged by previous aggressive cleaning, with the red ground layer being clearly visible through it, especially in the dark background area. In many areas the paint was covered with fillings and overpaints, with a thick layer of darkened and yellowed varnish and surface dirt on top (Fig. 5 and Fig. 6). Figure 5 • Detail of ‘The Dead Christ’ during the cleaning and after the treatment
Retouching relegious paintings – examples from private practice 223 During the cleaning process it was possible to remove only some of the fillings and overpaints (Fig. 5). Since those were firmly attached to the underlying layer and weren’t covering large surfaces it was decided to keep them. Extensive damage and losses had to be reduced throughout the retouching process (Fig. 5). The painting was lined using Beva 371. Losses in the ground layer were reconstructed using rabbit glue and Bologna and Champagne chalk, toned to match the colour of the original layer. An underpaint Maimeri® gouache-tempera layer was used only to define the main forms and shadows, thus leaving the possibility of imitating the overcleaned paint layer during retouching. The painting was varnished with 20% dammar in double rectified turpentine with the addition of 2% Tinuvin 292. The final retouching was done using Maimeri® restoration colours. The addition of a dammar solution for increased gloss was necessary in all parts of the polychromy. The retouching was done with various graphic forms (dots, dashes, lines, spots) and applied irregularly to match the badly damaged and altered polychromy, leaving the toned ground layer slightly visible where necessary (Fig. 5 and Fig. 6). Figure 6 • ‘The Dead Christ’ before and after the treatment
224 Lana Kekez | Kristina Krivec | Julija Baćak 5. CONCLUSIONS When dealing with paintings from church interiors it is necessary to take into consideration that they are a subject of veneration. This usually means a complete reconstruction of the missing parts is required whenever it is possible. Old photos taken before the damage prove highly valuable in such cases. Decisions about reconstructions of the missing polychromy, about the appropriate methods, techniques and materials, should be made by a group of experts. In all three cases the mastic based Maimeri® restoration colours, activated with butanol, were used for retouching and were applied on top of the isolating varnish layer. As expected, the colours were semiglossy to matt in appearance. In the first case, where Paraloid™ B72 was used, the gloss of the retouching colours matched that of the varnish, excluding the need for additional medium. In the second and third case, where dammar was used as an isolating varnish, it was necessary to add some extra dammar solution to the retouching colours, especially in the darker areas. The gloss of the mastic based Maimeri® restoration colours empirically proved closer to that of the synthetic polymer resin Paraloid™ B72, than to that of the dammar, a natural low molecular weight resin from the same group of terpenoid resins as mastic. To match the texture of the original paint layer and to blend reconstructed areas with the surrounding original, different techniques were used. The chosen technique (pointillism, tratteggio or combination of various graphic forms - dots, dashes, lines, spots) depended on the characteristics of the original painting technique, as well as on the changes in the paint layer texture and appearance caused by ageing, degradation and previous treatments. REFERENCES [1] All three conservation treatments were funded by the Ministry of Culture of the Republic of Croatia, through its regular movable cultural heritage conservation funding programs. On behalf of the Ministry, the supervision of the treatment was carried out by conservators in charge. In the case of Saint John the Baptist, the painting conservators were Ivan Alduk and Katarina Cvitanić from the Conservation Department of the Ministry of Culture in Imotski. For the two paintings from Šibenik, The Dead Christ and Virgin Mary and Child, the conservator in charge was Diana Bolanča from the Conservation Department in Šibenik. [2] Maimeri® Restoration Colours data, Talas, Official website of Bookbinding, Archival & Conservation Supplier, Available at: http://www. talasonline.com/Maimeri-Restoration-Colours [12 March 2018] [3] The Photo Archive of the Split Conservation Department of the Ministry of Culture, Inv. num. 84716, Neg. num. L-25935, taken: J. B. 10/87. [4] Maimeri® Gouache-Tempera data, Maimeri, Official website, Available at: http:// www.maimeri.it/en/products/gouache/ maimeri-gouache.html [12 March 2018]
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Abstract The mural paintings in the chapel of Saint Michael are a unique example of artistic quality in Catalonia that combines local tradition with painting techniques of Toscana 1300 [1]. They have survived in a good state of preservation in a small cell attached to the cloister. However, some alterations due to ageing of the materials and the consequences of different treatments carried out in the past can be observed. A key aim of the conservation project was the removal of the altered colour retouching made with vegetable gum and other semi-soluble binders [2] applied in earlier interventions on gypsum mortars that fill the gaps, such as the restoration carried out by Arturo Cividini near 1929 [3] or the recent one conducted by Diputació de Barcelona around 1951. The restoration group coordinator has considered the nature of the materials to be used, valuing their full compatibility with the original technique, maximum durability and sustainability. The reintegration of large areas decorated with geometric motifs, using discernibility criteria, combining fresco and secco techniques, has led to an innovative use of calcium hydroxide CALCIUM HYDROXIDE NANOPARTICLES FOR WALL PAINTING RETOUCHING. THE CHAPEL OF SAINT MICHAEL IN THE ROYAL MONASTERY OF PEDRALBES, BARCELONA. Rosa Senserrich-Espuñes (1) | Lídia Font-Pagès (2) 1. Department of Arts and Conservation, Faculty of Fine Arts, Pau Gargallo 4, 08028 Barcelona (Spain), [email protected] 2. Conservation Service, Barcelona History Museu, Llibreteria 7, 08002 Barcelona (Spain),
1. INTRODUCTION This work is an account of pictorial retouching of large lacunae affecting geometric motifs and false marbles decoration that frame the scenes of the wall painting in the chapel of Saint Michael, 1346. [Fig.1]. nanoparticles [4]. Nanolime dispersion was used to fix the high-quality pigments in the second phase of retouching of the extensive areas derived from the substitution of the incompatible mortars [5]. This system offers a greater duration of retouching: high resistance to the alterability caused by light, no yellowing or colour changes, and low risk of becoming a focus for the development of microorganisms in the event of any adverse environmental conditions. Keywords Wall Painting; Trecento; Barcelona; Colour reintegration; Calcium hydroxide nanoparticles; Nanorestore® This treatment replaces an earlier one, carried out in about 1929, made with semi-soluble vegetable and protein binders. It was decided to remove because it showed chromatic alteration and because it had been applied on a plaster reintegration that needed to be removed as well, since it contained soluble salts that could damage the original lime mortars. Two important factors have been taken into account in choosing the type of retouching: 1. The fact of certainly knowing what the missing decorative motifs are. It was not necessary to resort to the hypothesis since there was Figure 1 • Deployed image of the mural paintings of the chapel, currently under restoration. a geometrical and easily repeatable pattern. 2. The mimetic retouching system from the 1929 intervention, to which the public that visits the chapel has become accustomed over the last century. The objectives of the pictorial retouching project have been the following: • Removal of the altered colour retouching. • Compatibility with the original painting (mixed fresco and secco technique, with presence of various binders such as oil and proteins). • Durability by selecting stable materials that do not undergo chromatic changes. This means avoiding organic binders that may be altered in conditions of high humidity or favour the development of microorganisms. This aspect is relevant because the paintings present some mottling caused by an ancient fungal attack and sensitive areas painted with organic binders, although they are highly mineralised.
228 Rosa Senserrich-Espuñes | Lídia Font-Pagès • Legibility for easy recognition, combining a mimetic retouching system with a final treatment that allows to distinguish the original parts of the reintegrated ones. • Re-treatability to guarantee that it can be retouched with a compatible secco technique in the future. • Sustainability for the restorer in charge of the intervention and for the environment. 2. MATERIALS AND METHODS The proposal is a retouching in fresco with a final treatment in secco using a nanolime dispersion (Nanorestore ® in isopropanol, code 01105901) [6] at a 1g/l concentration. This dispersion is mixed with lime compatible pigments, and the final adjustments are applied by means of several vertical lines, separated by a distance of approximately 2mm, which facilitate a rapid recognition of reintegrated areas and provide discernibility to the retouching system. These vertical lines are combined with the previously applied flat colour inks, harmonizing the result with weathering and alteration of the original painting. In addition, retouching with pigments and a nanolime dispersion provides more time for intervention and does not interfere with the preceding pictorial strata made in fresco. Retouching method of large lacunae in cosmatesque friezes The followed retouching method is based on two stages: the first one is carried out with a fresco technique on a lime mortar developed specifically for this procedure. The second one is carried out with a secco technique, using a calcium hydroxide nanoparticles dispersion as a binder. At the end, the two phases should show a strong cohesion due to their full compatibility. [ Fig.2 a,b-3]. FRESCO PROCESS (for backgrounds): 1. Application of a lime and sand intonaco. 2. Application of lime-based whitewash to create the chromatic base of the frieze. 3. Stencil with ochre pigment to distinguish it from the original black carbon stencil. 4. Application of the background colours with diluted compatible pigments in water (ochre, iron oxides, vine black and white lime) SECCO PROCESS (for intermediate and final touches): 5. Application of a grey cerulean blue tone, mixing the pigments with the calcium hydroxide nanoparticles dispersion. 6. Drawing of multiple vertical blue lines. 7. Drawing of multiple vertical raw umber lines, to tint brightness of previously applied inks, integrating new areas with the original ones. Figure 2 a,b • Fresco process Figure 3 • Secco process
Calcium hydroxide nanoparticles for wall painting retouching. The chapel of saint michael in the royal monastery of Pedralbes, Barcelona 229 The same retouching system followed in the friezes has been applied to the missing false marbles of the wainscot, adapting the chromatism according to the zone. 2.1 Analytical test to evaluate nanolime behaviour A reintegrated area with the retouching system presented has been analysed [7]. The used techniques were Optical Microscopy (SMZ800 Nikon Stereomicroscope and Nikon Eclipse LV100 Microscope) and X-ray microdiffraction with synchrotron light SR-µXRD, line XALOC BL13 (ALBA synchrotron, Cerdanyola del Vallès). In this case, the measures were taken by transmission. The results confirm that a continuity of calcite is observed throughout the depth of the sample, with a higher proportion of calcium carbonate in the mortar. No discontinuity is observed between the first and second retouching layers (fresco and nanolime reintegration) [Fig.4 a,b]. 3. RESULTS AND DISCUSSION Organic binders have been dispensed with, choosing a retouching based on the carbonation of calcium hydroxide. The use of lime and nanolime offers a result that fulfils the initial established objectives. As regards the fresco retouching, durability is guaranteed. As regards the retouching in secco, nanolime has an appropriate behaviour as a binder for mineral and compatible pigments, mixing well in the palette and facilitating the drawing of lines. If any rectification is needed, lines can be erased using a moistened cotton swap with distilled water before the carbonation process starts. The cohesion between the nanolime and the retouching in fresco is good and, after a year, no detachment between layers has been observed, thus ensuring the long-term durability of this chromatic reintegration. This method of retouching is related to medieval painting in mixed technique, giving a predominantly matte appearance. Figure 4 a,b • X-ray diffraction: 3D distribution profile of crystalline compounds of a sample cross section (a). Micro sample of a retouched area: Lime mortar/Green earth, background/Raw umber, vertical lines (b). 4. CONCLUSIONS The retouching made with fresco technique presents an important challenge. It requires a considerable skill in this pictorial procedure and confident assurance in colour application. In return, it offers maximum guarantees of durability, reducing the need for further intervention in medium term. Retouching with nanolime on reintegrated areas in fresco allows adjusting and tinting the base inks, also based on the carbonation process. Retouching without organic binders is especially interesting in places with a high RH such as Barcelona, an area with a Mediterranean coastal climate where high levels of humidity can be reached. This system reduces the risk of microorganism proliferation [Fig.5,6].
230 Rosa Senserrich-Espuñes | Lídia Font-Pagès 4.1. Acknowledgments: To Markus Eiden, conservatorrestorer of mural painting who has put into practice its expertise on the fresco technique and has made this reintegration system possible. To Anna Castellano, director of the “Reial Monestir of Santa Maria de Pedralbes” for believing in this intervention. Figure 5 • Central wall with pictorial reintegration completed. © Photo Josep Casanova Figure 6 • UV light: the darker areas in the wainscot and friezes correspond to the surfaces reintegrated with the proposed method. © Photo Josep Casanova
Calcium hydroxide nanoparticles for wall painting retouching. The chapel of saint michael in the royal monastery of Pedralbes, Barcelona 231 REFERENCES [1] FONT, Lídia; SENSERRICH, Rosa – The conservation of the paintings in Saint Michael’s chapel in the Monastery of St Mary of Pedralbes. In FONT, Lídia, ed. – Conserving Trecento mural paintings. The role of painting technique. Barcelona: MUHBA Documents, Ajuntament de Barcelona, 2015, pp. 70–83. [2] ARTE-LAB SL – Estudio de los materiales orgánicos presentes en diez muestras tomadas de los murales del Castillo de Pedralbes. Unpublished report, Madrid: Arte-LAB, SL, 2012, pp. 12–13. [3] TRENS I RIBAS, Manuel – Ferrer Bassa i les pintures de Pedralbes. Barcelona: Institut d’Estudis Catalans, 1936, pp. 29–30. [4] BAGLIONI, Piero (et al.) – Consolidation of Wall Painting and Stone. In BAGLIONI, Piero; CHELAZZI, David; GIORGI, Rodorico ed. – Nanotechnologies in the Conservation of Cultural Heritage. A compendium of materials and techniques. Dordrecht: Springer Science + Business Media, (2015), pp.15–59, doi: 10.1007/978-94-017-9303-2 [5] SENSERRICH-ESPUÑES, Rosa – Il Restauro delle pitture murali della capella di Sant Miquel, Monastero de Pedralbes di Barcellona. In PFEIL Mathias, ed. – Retrospektive & Perspektive. Methoden und Techniken in der Wandmalereirestaurierung. (Schriftenreihe des Bayerischen Landesamtes für Denkmalpflege, Nr. 17). Werkstattgespräch 9. und 10. Mai 2016. München: Volk Verlag, 2017, pp. 202-216. [6] CTS Srl. Official website, Nanorestore® Technical Data Sheet. Available at: http://www.ctseurope.com/en/schedaprodotto.php?id=232 [28.01.2017] [7] SALVADÓ, Nati; BUTÍ, Salvador – Informe 2017 (II). Pintures Murals de la capella de Sant Miquel del Monestir de Pedralbes. Unpublished report, Vilanova i la Geltrú: Department of Chemical Engineering. Polytechnic University of Catalonia - Barcelona TECH, 2017, pp. 22-–27.
Abstract The paper discusses the particularities of a retouching case on a rare object, a 19-th century double-sided flag used in religious processions of the Orthodox Church as part of a distinctive ritual within a rural agrarian community of Southern Romania. Along with surface deposits and evidence of aged paint, the major issues of aesthetic concern appear to be random traces of dripping paint occurring from architectural renovations and more particular, areas with mechanical compression caused by past inadequate attempts of scraping that paint material from the original pictorial surface. A high glossy surface, multidirectional polishing marks, and a disturbing contrast of texture interference on original material in paint show as consequences of the damage drawing a pole of discussion around the conservation approach of the icon, its visual compensation, focusing on the methodology and materials needed to perform a satisfactory chromatic and morphological reintegration of this artwork. Considering the irreversible mechanical compression of paint material and its undesirable effect on the compositional syntax of the religious image carried during the outdoor processions, relevant details from the two compositions needed to be visually restored in order not to affect the ritual function of the icon. After preliminary RETOUCHING A DOUBLE SIDED 19TH CENTURY PROCESSIONAL FLAG-ICON Filip Adrian Petcu Timisoara Museum of Art; Piata Unirii nr. 1, 300085 Timisoara, România; E-mail address: [email protected] , , ,
1. INTRODUCTION 1.1 The flag-icon and its ritualic function Double sided painted processional flags from the mid of the 19th century are quite a few well preserved in Romania. If we still find such artefacts in local churches, most of them are in an alarming state of preservation, due to specific reasons regarding the study tests over retouching options, observed in optical microscopy, using several synthetic resins in solutions, Paraloid® B-72, Paraloid® B-67, Aquazol® 200, Aquazol® 500, Laropal® A-81 and an acrylic dispersion (EA/ MMA, CTS® ACRIL® 33), one choice seemed to match the requirements. Paraloid® B-72 gelled with fumed colloidal silica, Aerosil200®, was selected as the optimal medium for retouching the degraded areas and creating an appropriate, satisfactory integrated texture, that was similar in its material consistency and structural appearance to the original surface. Keywords Double-sided processional flag-icon, compression of paint, Resin retouching, Paraloid B-72®, Aerosil 200®. critical conditions of their current use and storage. Processional flags were intensively carried during various annual religious processions, but also occasionally during military events, riots, revolutions and wars, as symbolic effigies of an emerging national consciousness in Europe and the Balkans starting with the mid of the 19th century. The present double sided processional flag is one of the rare examples of that kind, carrying even more an authorial inscription, commemorating three iconographers -George, Kostandin and Kostandin (Zugravi). The painters are mentioned together with the inscription of the year 1848, which points presumably to the date of commission. The inscribed text is recorded on the front side, along with the text of the troparion of the depicted festal icon, with black characters on a yellow background, marking a painted frame which encloses the composition of the Theophany. The object depicts on its verso a double portrait of two juxtaposed patron saints related to the autumnal time of the harvest: the full figure portrait of Saint Martyr Tryphon of Campsada, Syria, accompanied by the Venerable Saint Petka (Paraskevi) from Epivato(Paraskeva of the Balkans). On the front side of the flag we find the representation of the festal icon of the Theophany, a typical composition with four figures in the presence of the descending dove as symbol of the Holy Spirit. The depicted scene refers to the Baptism of Jesus Christ in the Jordan River, event celebrated in the Orthodox Church on the 6th of January (Gregorian Calendar) or the 13th of January (Julian Calendar). This feast includes the blessing of the waters and rivers in the name of the Holy Trinity by the participating clergy and the local community engaged in a large procession which accompanies the ritual commemorating the restoration of the cosmos through the redemptive mission of the incarnation of Jesus Christ the Divine Logos. In this context the carried flag is invested with a symbolical significance which points to the seasonal cycles in an agrarian society, the rebirth of the creation, the blessing and working of
234 Filip Adrian Petcu the land and the annual harvest of the crops, as an anthropological reference to the human passage on earth, in perspective of the promised harvest of the afterlife. Considering its thematic substance, this painted flag used to be also carried in religious processions during the blessing of the agricultural fields, when lands were sprinkled with holy water, not only at the moment of the very feast of the Theophany, but also during several other special days of the year, as are, in spring, the first Friday after the feast of the Resurrection of Christ and in autumn, the feast of the Exaltation of the Holy Cross, as well as during occasional times of drought. 1.2 The object. Origin and preservation The object of our reference was initially preserved in a wooden church in Țara Românească, the county of Gorj, the commune of Bărbătești, the village Socu, where it suffered several degradations due to various specific functional contexts occurring in such wooden churches. A few decades ago the flag was saved by a local, belonging to the community of the village, prior to the demolition of that church, when the object also became part his private collection, preserving the memory of its context and history. As expected from such cultic objects used both indoor and outdoor, they were constantly subjected to mechanical movement, tensile stress and thermal expansion during their translation in processions, when such flags were frequently exposed to critical variations of the environmental parameters. The object indicates, on both of its sides, visible structural damage of the textile support, along with other specific marks of material degradation through mechanical stress, with a considerable impact on the pictorial surface and the physical appearance of the depicted images, both on front and rear, altering the morphology of the painting. The conservation issue of the flag became therefore a challenge, not only from a technical and methodological perspective, but also from a conceptual point of view, considering its cultural identity, as well as its actual purpose. The processional icon on a textile support is a cultic object in the first place and the liturgical function of the icon within the Christian Orthodox ritual remains to be considered as essentially in formulating a concept over the conservation treatment and the final presentation of the restored object. 1.3 Icons and restoration in Romania The process of restoring religious icons in Romania is very representative and particular for the country’s identity and culture. The large fund of painted artefacts from the current public collections and state museums in Romania are mainly icons, mostly late- and post-Byzantine icons, initially property of the Orthodox Church in Romanian. In the course of the 20th century a considerable number of icons originating from remote churches became part of newly founded local public collections, county museums and national museums. The artefacts were selected from various monasteries and churches by professionals who carried field campaigns, purposing to identify valuable objects, to be saved, conserved and further meant for public display. Many of these artefacts were collected in central storages, where proper preservation measures were not always met, a reason for which the conservation of these artefacts became an issue with time. The number of professionals in museums was far too outnumbered to cover the needs for the amount of objects which needed treatment and only few restorers could benefit from a professional mobility abroad, at a time when Romania was segregated behind the Iron Curtain, up to December 1989. The conservation methodology for icons employed in Romania followed mainly the Russian school of
Retouching a doble sided 19th century processional flag-icon 235 restoration [1] and only later, starting the 70s, it began to adopt tendencies of the school of Rome [2]. Up to this day the local trends in conservation tend to suggest almost exclusively the use of classical natural materials in the treatment of icons, particularly for the consolidation of paint layers and retouching operations. [3] Relying during the past decades on the Charter of Venice and the theory of Cesare Brandi, some of the restorers and art historians started to appreciate the concept of the minimum intervention, stating that less aesthetic intervention on icons would be rather more preferable for the sake of preserving authenticity of icons. This attitude proved to be obviously in contradiction to the official point of view of the Church which highlights the importance of the cultic function of the icon, supporting rather more an aestheticizing restoration of a formal integrity, as much as possibly agreed, in respect of the depicted subject of the image. The icons of the saints are part of the church ritual already for two millenia. There is always a persistent debate between two possible arguments of choice on how to restore icons: the archeological presentation, advocated by museum professionals, and the aestheticizing “reasonable” inpainting of icons kept in churches, which are meant to be restored to “their original beauty”. These make the two irreconcilable poles around the debate. Traditionally, icons are painted with natural materials, as they symbolize in their process the sanctification of matter through the synergic work of the human iconographer and the consenting blessing of God. There is a theological argument supporting the use of natural materials in the conservation of icons, making them more preferable against synthetic resins [4]; however, natural materials have their limitations due to their inherent properties. Natural materials are generally preferred in conservation treatments in Romania, as opposed to many synthetic polymers which are avoided apriorically by most of the local conservators. The apparent reason for a sceptic attitude in Romania, towards the uprising world of synthetic materials in conservation, was taught to be rejected with the implacable argument of the unpredictable ageing of these new materials, the compatibility issues and their questionable reversibility. Considering this approach, the process of inpainting records, on national level, either the use of plain commercial watercolours, tempera with egg yolk and dry pigments, or watercolours blended with a lean egg yolk emulsion. These record presently to be the common acceptable options for retouching icons in Romania. Polysaccharides and lipids, or denaturated proteins are the ingredients of the two historical media that were used by artists and are still acceptable for retouching, if used properly.[5] There are also occasionally rare cases when commercially available oil colours are drained on blotting paper from their excess of oil binder, being sometimes blended with resinous varnish (damar or mastix) for inpainting over older wax fillings. In rare situations some restorers use modern mastix retouching colours from the Maimeri Restauro® line to inpaint icons. In terms of methods of inpainting in Romania, differentiated retouching by optical division is preferred against the standard or mimetic type of retouching. Variations of the Roman vertical linear crosshatching, trattegio/ rigattino, sometimes combined with thin velatura/glazing or alternated with pointillistic rittocco/puntinato are generally applied, in lighter, cooler undertones of colour, for the visual compensation of either micro losses or larger lacunae. The inpainting occurs mostly on flat, unstructured white infillings, leveled at the even surface of the surrounding original paint or slightly below it, favouring generally a standard recipe for the putty. The putty is based
236 Filip Adrian Petcu essentially on proteic glue solutions with micronized calcium carbonate or calcium sulphate in suspension. In some cases of retouching paintings on walls of wooden churches, distemper paint is applied in thin washes directly on the bare wooden support, by means of low concentration of proteic glue suspensions and dry pigments, in addition to a bactericide, antifungal agent. Although egg tempera can give the possibility to emulate various textures, refering all these aforementioned practices of retouching icons in Romania, there is apparently no concern over the integrated texturing of the matter which builds the support for the retouching, nor over the texture of the retouching itself. The tendency is rather a conceptual emphasis on highlighting, by means of the inpainted areas, a different, discernable texture of the restored parts, distinguishable by the optical division retouching method of the flat putty. In our opinion this approach can lead to a difficult legibility of the image and to an unsatisfactory contrast between different textures, the flatness of new fillings with their corresponding inpainting and the micro relief of the original paint film. Watercolour alone cannot support building of structured films, while egg tempera can become brittle with time and can delaminate easily if the emulsion is not properly adjusted within the layering system. In this regard we agree that synthetic resins can offer superior solutions to build up proper textures of the inpainted areas, flexible structured films, with accurate tone adjustments, aesthetically matching the original paint. [6] The later options are always easily discernable by means of non-invasive optical investigation. Tested synthetic resins, as recorded by recent professional literature, can provide a base for properly structured fills, providing a stable film for the retouching colour. They can be adjusted to the appropriate hue and tone, while matching in gloss and transparency the exact, specific expectations for the chromatic completion. Therefore, since 2006-2007, within the West University of Timisoara, Faculty of Arts and Design, Conservation Department, we were the first professionals in Romania to test and employ modern retouching media on icons, based on PVOH like Mowiol® 4-88, PVAC(since 2006) colours as LeFranc&Bourgeouis Flashe®(since 2006) and resinous mediums based on HMWR and LMWR, synthetic polymers and oligomers, as are Paraloid® B-72 (since 2008), Laropal® A-81, Regalrez® 1094 and PeOX Aquazol® (in different molecular weights, 200, 500), on synthetic thermoplastic fills, considering the different properties of these materials, their corresponding class of stability, their versatility, role and advantages as useful, employable binders in the inpainting process.[7] We tried to use these materials in differentiated inpainting techniques as well as in standard retouching, considering the importance of the visual appearance of the texture of the fillings, as also the structure of the inpainting colour supposed to match the original paint.[8] These later aspects are key elements to define a final impact on the visual presentation of the restored artwork, its perception and legibility, paying proper tribute to the function of the image as a cultic object, whereas not neglecting Brandi’s paradigm, which defines the work of art by means of its polar, historical and aesthetical instance and significance. 2. MATERIALS AND METHODS 2.1 The condition of the object Except for some minor losses on the perimeter of the textile support of our flag-icon, the canvas showed several structural deformations, planar distortions, consistent warping, small tears and massive buckling due
Retouching a doble sided 19th century processional flag-icon 237 to its original suspension system over a hand carved wooden spindle. This element supported the upper edge of the canvas to hang from above on a taller handle, presently lost. The horizontal wooden element carries a central drilled hole, as a fixing point addressed to the insertion of the vertical handle used during processions. On its upper edge the canvas is tied by means of a helix-sewn hemp rope to the auxiliary horizontal element, a spindle carved in hard wood. The textile rope became with time oxidised and loose and imparted an unappropriate tensile force to the painted canvas. The textile canvas is made from two sewn pieces of linen fabric. It is unprimed and shows a prominent texture of its weaving carrying mainly a thin to mediumthick paint layer with rare accents of impasto. Some areas of such impasto, particularly on carnations, have been lost probably during movements of the textile support in conjunction with the embrittlement of the aged proteic and lipidic original medium, which flaked off. The surface`s appearance indicates the overall presence of a dark brownish oxidised skin of medium covering the pictorial surface, together with embedded carbon particles and dust, visibly impacting the overall perception of the composition. The texture of the painted surfaces had a waxy tactile feel, which might suggest the possibility of use of a waxy medium as a protective coating. The main issues concerning the legibility of the images on recto and verso, consist in areas with residues of dripped light blue paint, which were spread irregularly over the surface and more particularly, marks from a former intervention which attests an invasive scraping of these dripping spots with a rigid tool and considerable mechanical pressure. The effect of this attempt to remove the stains effected irreversible consequences on the paint layer and support, compressing the paint and transforming the original texture of the canvas weaving into a polished, glossy burnished surface with diagonal polishing marks, particularly discernable in raking light. The burnished areas carry the imprint of the metallic instrument used in the previous cleaning attempt and require an adequate aesthetic compensation through chromatic retouching and textural integration with an appropriate retouching medium and a dedicated technique. 2.2 Methodological explorations Our treatment had to consider the structural conservation of the canvas, the consolidation of the endangered areas of impasto paint, the surface cleaning of the painting on both of its sides and the aesthetic compensation on the damage. The main issue consisted in the reduction of the aesthetic dissonance, the textural contrast between the irreversibly compressed, burnished damaged original paint and the pristine surface with fabric texture. The paint was tested for water and organic solvents sensitivity and proved to be quite hydrophobic. Following the criteria of a necessary permanent flexibility for the support, the consolidation of the paint layer was performed with a diluted BEVA® 371b solution in Thinner 372®, followed by local ironing and drying under pressure. Selective organic solvents were successfully employed in the cleaning process, which meant basically reducing of the thickness of the darkened surface coating, excessively oxidized in some of the compositional areas. Mixtures of naphta solvent, acetone and isopropanol, both in liquid and gelled form were used in conjunction with aqueous gels of buffered 1-2% triammonium citrate solutions, in a range of pH from 5.5 to 8.3, embedded in a Lubrizol Permulen® TR2 gel. The residues were rinsed carefully from the surface with deionised water and aliphatics. Using the same initial principle,
238 Filip Adrian Petcu the canvas was reanchored on its upper edge to the original spindle-shaped horizontal wooden element, adjusting an acceptable tension by means of inserting a similar new hemp rope, which replaced the damaged previous one. The rope was infused with Paraloid® B-72 for its hygrophobisation and the stabilisation of the textile threads. There was no need to use any putty to infill the losses, simply because a good tailored inpainting medium could replicate closely the needed texture, achieving a good compensation of the compressed, burnished areas of damaged paint. Paraloid® B-72, a class A stability polymer, additionaly stabilized with a Hindered Amine Light Stabilizer, Tinuvin® 292, represented our choice for the isolating varnish, applied in a thin coating dissolved in Ethyl Acetate(BP 77.1 ̊C). The separating varnish was meant to protect both sides of the painted canvas before the retouching process. Several tests, as resulting from Table 1, were performed to establish the better choice for a structured inpainting medium, one tailored to match an appropriate textured surface during further retouching The tests were observed under the microscope with different magnification, to select an optimum binding material for the inpainting of the aforementioned areas. The potential choices for the visual compensation of the texture difference issue were considered on matters of stability of the resins, as well as on the evaluation of physical and optical properties like rheology of the medium, flexibility of the film, drying time, workability, removability, opacity, transparency and gloss matching. We established some requirements which would define suitable expectations for our retouching medium in case of our flag-icon: the medium should easily adhere to the original surface without damaging it, it should have good thixotropic qualities and a medium gloss when used in a very viscous form, as also a minimum shifting of tone after drying, it should be employable in an transparent or an opaque form, it should dry quite fast and stable without excessive swelling of the underlayers, it should be lightfast and photo-chemically stable, it should preserve its flexibility features, cohesive and tensile strength, even in potentially oscillating slightly damp environmental conditions and it should remain easily removable on long term; it should conform in texture and structural appearance to the imprint of the original transfer tool, preserving crisp, sharp details of the application tool; the retouched areas should not be affected by the solvent of the final varnish and should remain permanently retreatable. 3. RESULTS AND DISCUSSION Different materials with various glass transition temperatures[9] were selected to be tested in various concentrations, as resulting from Table 2. An acrylic dispersion of EA/MMA, CTS® ACRIL® 33 was tested in its pure form, as well Table 1 • Ratios of resin:solvent:additive (v/v; w/w)
Table 2 • Index of the tests. resins & their solvents Retouching a doble sided 19th century processional flag-icon 239 as in a 1:10 V/V dilution with deionized water. As further options were considered: 20% w/w acrylic solutions of either, Paraloid® B-72 (RI 1.47-1.48), a short chain acrylic ester and Paraloid® B-67(RI 1.48); a butyl metacrylate polymer,[10] in Butyl acetate; a 20% w/w urea-aldehyde resin, Laropal® A-81 (RI 1.50) in Isopropanol; 40 % w/w solutions of PeOX , Aquazol® 200 and 500 (RI 1.52), both in pure form, as well as a mixture of both, in a 1:1 ratio, dissolved in an 96% Ethanol hydroalcoholic solution. Finally, an additionally modified stock of Paraloid® B-72 20% w/w solution was improved with the addition of an inert, stable material, 0.6 g hydrophilic fumed colloidal silica, Evonik Aerosil® 200, blended with a Cappucino mixer into 12 g of 20% w/w B-72 solution. Hereby were improved the rheological properties of the medium and adjusted the gloss of the binder, while managing also the solvent’s evaporation rate. Fumed silica is known to “distribute any stress or strain during the solvent evaporation and setting” of the B-72 medium [11], imparting body to the medium. The prolonging of the workability of the gel was adjusted with a minimal addition of Propylene glycol monomethyl ether, Dowanol® PM (BP 120 ̊C). Butyl Acetate (BP 126.1 ̊C), Isopropanol (BP 82.3 ̊C) and Ethanol(BP 78,1 ̊C) were chosen for their low moderate swelling action on oil films, considering a decreased risk of swelling in the presence of B-72 varnish as a separating, isolating layer. The corresponding boiling points of these organic solvents allowed us to appreciate an acceptable grade of workability of the mediums during their application. All the mediums were tested individually, both in their pure form, as also blended with dry pigments, PR 10 and PR 194, from Kremer Pigmente. These were applied with brushes and spatulas on glass lamellae, as in Figure 1, being further subjected to optical examination Figure 1 • All media texture samples on glass lamellae to be studied under magnification
240 Filip Adrian Petcu under the microscope. The samples were observed using a Carl Zeiss Axio Imager A1m microscope, using RL and 3200 K and the BF Mode, with four different lenses: Epiplan 10x/20 HD, Epiplan 20x/0.40 HD, A-Plan 20x/0.45 and A-Plan 40x/0.65 and only the B-72 gel indicated to preserve the required structure as defined in the earlier stated requirements. The aqueous dispersion of CTS® ACRIL® 33 had a good adhesion on the support in its pure form, but not really in the diluted form. It did not conform in texture or gloss to the expectations of our retouching standard, neither did it preserve sharp details of the brushwork. Paraloid® B-67 (iBMA), having a Tg of 50 ̊C, was excluded not due to its hardness alone but also due to its crosslinking potential which would make it decrease in solubility with time, threatening a future removability. Although Laropal® A-81 was characterized as a resin with great chemical stability and remarkable optical properties when compared to natural resins, it seemed here though quite glossy for our requirements, when applied according to the referenced viscous consistency. With a Tg of 49 ̊C, higher than that of B-72, Laropal® A-81 solutions need very low resin concentrations to decrease Figure 2 • B-72 inpainting gel under magnification
Retouching a doble sided 19th century processional flag-icon 241 in gloss and to achieve a slight mattness of paint, without any additives. In the present case Laropal® A-81 medium has a far too glossy texture when used with the needed viscosity to match the original colour’s structure. It definitely needs some developments to modify some properties within the stock medium. These include possibly additives, like a matting agent, blending of another resin a.o., either in order to decrease its refractive index or to balance the equilibrium between its gloss and consistency, while allowing to better achieve a structured relief of the paint at a lower level of gloss. The three Aquazol® solutions, using two different molecular weights of Aquazol®, 200, 500, were used individually as well as in a 1:1 ratio of 200:500. Aquazols have similar Tg, between 69-71 ̊C, obviously higher than some of the previous referenced resins, therefore we could expect possibly an increased brittleness as compared to the other materials, like B-72. A harder resin would not be suitable in any case in conjunction with our quite mobile textile support of the flag-icon. Beside these aspects we must record the hygroscopicity of Aquazol® which suggests the necessary addition of successive protective coatings to minimize its exposure to excess moisture from the atmosphere during potential processions with the flag, even though there are records which point to a certain stabilization of the resin due to the presence of unbound metal ions in pigments [12]. In respect to the acrylic dispersion, CTS ACRIL® 33, we appreciate that it has a far too low Tg, between 6-8 ̊C, which can conduct for the medium to attract impurities from the atmosphere. Moreover, unmodified ACRIL® 33 did not seem appropriate to create a sharp structured texture for a retouching. The standard Paraloid® B-72 medium, based on the acrylic HMWR copolymer(MA/EMA) in Butyl acetate [13], had a good adherence, slightly higher gloss than particularly required for the present case and it did not conform to our criteria regarding structural mobility of the medium, textural workability and fidelity of imprint of the application tool. These desirable properties required more than a basic retouching varnish, some particular improvements with special Figure 3 • The process of retouching and its results
242 Filip Adrian Petcu bulking materials, as already some commercially available retouching gels contain [14]. Therefore, close to our formulated expectations was the same Paraloid® B-72, dissolved in a 20% w/w, resin to solvent ratio, in Butyl Acetate, rheologically modified to a form a gel, bulked with a thickener and matting agent through the addition of hydrophilic fumed micronized silica. This improvement created a manageable, workable, structured medium, with better matching optical properties, an optimum drying time and a slightly reduced gloss. Colloidal fumed silica has an open internal structure which “is produced as a result of the formation process, where silicon tetrachloride and other volatile silanes are oxidized in a high temperature flame aerosol process to produce small, essentially spherical primary particles which subsequently collide to form rigid, covalently bonded aggregates”.[15] The use of fumed silica within the structure of the gel allowed us to replicate an adequate textured relief and a satisfying surface effect, which retained the impression of the brush stroke while matching closely enough the local relief of original paint, as initially applied by the iconographer on the canvas support. The test proved aesthetically compensatory, as resulting also from Figure 2 and seemed quite compatible to bridge between the areas of paint damaged by excessive burnishing during the past amateur cleaning attempts and the original textured painted surface of our flag-icon. Shrinkage of the paint medium was not an issue at this time, neither during, nor after the solvent evaporation, due to the reduced volumes of gel paint necessary to build up the structure of the retouching. Therefore, evaluating potentially negative effects after solvent evaporation from the retouched areas, no relevant changes in volume of the added paint became visible, nor did solvent evaporation negatively impact the visual compensation through inpainting of the damaged areas, particularly if we record that our retouching was built up layer by layer. 4. CONCLUSIONS Although, traditionally retouching media, like watercolour and tempera, have consequently proved their stability in the methodology of retouching and have certainly also gained the trust of many restorers over decades, there are still situations when the physical properties of such media reach certain limitations and can therefore be replaced by different media. Resin retouching media based on B-72, now already about 70 years old, offer great advantages and a vast multitude of improvement options through possibility of adjusting the given properties with stable additive materials. These can help the design and the precise tailoring of more efficient systems. Nevertheless, theory alone and certain recipes cannot entirely cover every need in this complex field, where individual testing and practice become crucial, as well as a continuously updated knowledge and knowhow. Hereby only, we can hope to manage and control parameters, the interaction effects between materials and the conjunctional role of every particular ingredient which is employed in the retouching strategy. In our current situation, starting from a basic formulation of a resin retouching method and following the guidelines of a gel recipe, by choosing slightly different solvents and inserting the appropriate additives, we could manage to implement a suitable method to fit our needs of visually compensating a particular damage, an inadequate compression of paint caused by a failed cleaning attempt. As a result of the process visible in Figure 3, the flag-icon was restored to a decent state of aesthetical condition, in respect of its material, historical and functional value.
Retouching a doble sided 19th century processional flag-icon 243 REFERENCES [1]ANASTASIU, Anastase, ed. – Restaurarea știință și artă, București, Muzeul de artǎ al Republicii Socialiste România, 1976. [2]MORA, Paolo; MORA, Laura; PHILIPPOT, Paul – Conservarea și restaurarea picturilor murale, București, Meridiane, 1986. [3]UNGUREANU, Cosmin – Anatomia restaurării, București, Muzeul Național de Artă al României, 2016. [4]PETCU, Filip Adrian – Paradigma icoaneirelicvariu. Structură tipologică în arta eclezială georgiană, Timișoara, Eurostampa, 2014. [5]JOLKONNEN, Nina; MARTISKAINEN, Auli; Martiskainen, Petter; Nikkanen, Helena ed. – The Conservation of Late Icons, UusiValamo The Valaamo Art Conservation Institute, 1998. [6]PETCU, Filip Adrian – Conservarea şi restaurarea unei icoane pe suport de pânză cu tema Răstignirea Domnului şi însemnele Patimilior Mântuitorului Iisus Hristos, In Caiete de artă şi Design, Nr. 3, Timişoara, Editura Eurostampa, 2016, pp. 59-66. [7] DIGNEY-PEER, Shawn; THOMAS, Karen;PERRY, Roy;TOWNSEND, Joyce; GRITT, Stephen. – The imitative retouching of easel painting. In STONER, Joyce Hill; RUSHMORE, Rebecca, ed. – The Conservation of Easel Paintings, London, New York, Routledge, 2012, pp. 607-634. [8]PETCU, Filip Adrian – Theoretical and practical considerations on the presence of lead soaps in the degradation of an 18th century oil painting on a copper support. In LOPEZ, Laura Fuster, BLANCO, I. C.; MARTIN, M. F. S.; Pascual, M. L. V. d. A; CARLYLE, L.; WADUM, J., ed. –Paintings on copper (and other metal plates). Production, degradation and conservation issues. ComunicaCC, Universitat Politècnica de València, Valencia, 2017, pp.145-152. [9]BORGIOLI, Leonardo; CREMONESI, Paolo – Las resnas sinteticas usadas en el tratamiento de obras policromas, Padova: Il Prato, 2005. [10]VON DER GOLTZ, Michael; PROCTOR, Robert G. Jr.; WHITTEN, Jill; MAYER, Lance; MYERS, Gay; HOENIGSWALD, Ann; SWICKLIK, Michael – Varnishing as part of conservation treatment of easel paintings. In STONER, Joyce Hill; RUSHMORE, Rebecca, ed. – The conservation of easel paintings, London, New York, Routledge, 2012. [11]KOOB, Stephen P. – The use of Paraloid B72 as an adhesive: its application for archaeological ceramics and other materials, In Studies in Conservation, 31:1, 1986, pp. 7-14. [12]ARSANOGLU, Julie – Aquazol as Used in Conservation Practice. WAAC Newsletter, Volume 26, Number 1, January, [2004], pp. 10- 15. [13]BESTETTI, Roberto; SACCANI, Ilaria – Materials and methods for the self-production of retouching colours. Laropal A-81, Paraloid B72, Gum Arabic and Aquazol based colours. In RECH2: Proceedings, 2nd International Meeting on Retouching of Cultural Heritage, RECH 2, Porto, Portugal, 24-25 October, [2014], pp. 26-39. [14]KONECZNY, P. – An introduction to B72 Retouching gels. Properties of B72 Retouching Gels and their use. In ELLISON, Rebecca; SMITHEN, Patricia; TURNBULL, Rachel, ed. – Mixing and Matching: Approaches to Retouching Paintings, London, Archetype Publications, 2010, pp. 142–158. [15]BOLDRIDGE, David – Morphological Characterization of Fumed Silica Aggregates. In Aerosol Science and Technology, Taylor44:3, [2010], pp. 182-186.
ABSTRACT The altar of the Assumption of the Virgin Mary, dated from the 18th century, is an example of the application of a different methods of retouching. The altar is part of the church of Our Lady of Konacvine in Seget Donji, Croatia. The aim of the final presentation of the altar was a different approach to the integration of the painted and gilded layers. After removing several coatings of overpaint we found that the main retable was originally gilded. The retouching approach was to fill the small lacunae with the rigattino method using tempera and the big lacunae with gold leaves. A marbled paint dominates the entire altar surface, whereas the damaged areas show a gilded layer, which has led SELECTING METHODS FOR RETOUCHING A POLYCHROME AND GILDED ALTARPIECE WITH ELEMENTS DATING FROM DIFFERENT PERIODS Sara A. Eterović (1) | Ivana Letilović (2) | Katarina Tomaš (3) (1) TiaArte, obrt za restauraciju/ Conservation and Restoration Services/, [email protected] (2) NeoRestaura, obrt za restauraciju /Conservation and Restoration Services/, [email protected] (3) GoldArt, obrt za restauraciju/ Conservation and Restoration Services/, [email protected].
1. INTRODUCTION OLTAR MARIJINA UZNESENJA ALTAR OF THE ASSUMPTION OF THE VIRGIN MARY The altar is made in polychrome, gilded and carved wood. The altar is composed of a predella decorated with medallions, and fluted half columns with Corinthian capitals settled on predella. The entablature rests on the columns and supports the pediment ornamented with decorative vases. The antependium is part of the altarpiece architecture, but it is stylistically different (Fig.1). to the assumption that the whole altar was originally gilded. The wooden polychrome antependium with marble effects, added in the late 19th century, was finally presented with the original polychromy. The missing parts of the paint were retouched with tratteggio using acrylic paint. Keywords Polychrome wooden altar; Retouching; Gilding; Conservation and restoration 2. MATERIALS AND METHODS 2.1. Stratigraphic analysis of the paint layer Upon examination of the polychromy, it has been determined that under the visible paint layer there was a layer of gilt. A stratigraphic analysis was done in order to establish the number of coatings and if the original polychromy still existed. The samples were collected in different parts of the altar and were examineted and photographed under a microscope (Fig.2, Fig.3 ). 2.2. Cleaning trials of the overpaint and examination of the paint layers Upon the stratigraphic analysis of the paint layers, by which it was determined the existence of an overpaint over the original polychromy and gilt, the examination of the state of preservation of this layers was also carried out. The analysis was done on different parts of the altar in order to establish the extent of preservation of the original paint layer and to find the appropriate method and material to clean it. Figure 1 • Altar of the Assumption of the Virgin Mary before conservation and restoration Figure 2 • Micro-section of the paint layer taken from the antependium Figure 3 • Micro-section of the paint layer taken from the entablature
246 Sara A. Eterović | Ivana Letilović | Katarina Tomaš Alongside with the examination, rehearsals for removing the overpaint were carried out. This tests were executed by using solvent gels and solvents that work on an oil-based overpaint. No water based solvents were used due to the presence of a water gilding which was found in the original paint layer (Fig.4). Tests using Pemulen Tr2 gels were performed in order to soften or remove the top paint layer, whereas the last layer should have to be removed with a solvent that would not damage the original gilt. During the application of the gel it was found that the overpaint was oilbased applied in combination with a binder, on which the solvents work poorly. It was assumed to be casein. After repeated attempts, it was possible to remove the overpaint. It was decided to maintain the recent layer of the antependium that has oil-based paint. In view of the fact that the original is also oil based, it was not possible to remove the overpaint without damaging the original polychromy. 2.3. Overpaint removal The overpaint was removed with an industrial oil-based paint removing gel. The gel was applied on the surface and left to rest for 15-20 minutes until the oil-based layer softened. After which it was removed with cotton balls. The remains of the paint were eliminated with acetone. After the use of these solvents the surface was neutralised with Shellsol T. 2.4. Retouching methods Before retouching, the reconstruction of the wooden structure was carried out and the surface was prepared. Altar A layer of bole poliment was applied on areas where golden leaves would later be placed. A red and yellow bole was used, which was toned with tempera in an attempt to reach a tone close to that of the original. The poliment was polished and prepared for gilding. Gold leaves (23 K ducat doppel) were applied using a water gilding technique. This gold differed from the original in tone and gloss. In order to match the new tone with the old one, newly gilded areas were toned with varnish based colours (Maimeri Restauro Varnish Colours). Smaller damaged areas were retouched with tempera colours with rigattino technique (Fig.5) and also using 23 K gold powder with 10% Paraloid B72 (solved in toluene) binder. This method was chosen because the retouched area is well visible from up close, and from a distance it nicely integrates with the original gilding which, in turn, emphasises the visual harmony of the entire altar. Antependium In view of the stylistic differences between the antependium and the upper area of the altarpiece, it was decided to retouch the lower element in trattegio using acrylic colours (Daler Rowney Acrylic colours), while maintaining the visual integrity of the set. (Fig. 6) The level of damage of the antependium was considerable and was caused by a direct contact with a Figure 4 • Examination of the paint layers Figure 5 • Retouching using rigattino - detail from the pediment. Figure 6 • Antependium after retouching
Selecting methods for retouching a polychome and gilded altarpiece with elements dating from diferent periods 247 Figure 7 • Altar of the Assumption of the Virgin Mary after conservation and restoration humid stone floor, which required the use of waterproof retouching colours. Different retouching approaches were used due to the texture of the paint layer and the level of damage (Fig.7). 3. RESULTS The use of different retouching methods were necessary in this case due to a number of aspects that conditioned the decision. In the choice of the retouching method, a special attention was paid to the variety of techniques and materials used on the altar. The decision on the techniques and materials depended on the degree of damage and on the position of each lacuna. The intended appearance of the altar after the restoration was a visual integration of the original gilt and the retouch from the viewer’s perspective, highlighting their difference at a closer look. The altar required re-gilding of the damaged areas and retouching of the original gilt, so we used a combination of two methods which, as a final result, proved to be an ideal solution. The antependium, which is completely different in style, was retouched with acrylic colours. The acrylic colours were chosen because of their waterproof quality, and due to fact that the antependium was in direct contact with a humid church floor. This altar was treated as two separate units. At the same time, it had to be taken into account that the altar should be presented as a whole and in connection with the other two altars in the church, belonging to the same period. REFERENCES Fisković, Cvito; Segetski Spomenici. Résumé: Les monuments de Seget. Vjesnik za arheologiju ihistoriju dalmatinsku, Split, LVIŠLIX/1954Š1957, vol. 2, pp. 213Š232, pp. 219-220 Ivana Letilović, “Conservation and Restoration Interventions to the Altar of the Assumption of Virgin Mary”, restoration documentation, 2015.
Abstract The aim of this article is to compile a list of materials that are acceptable for the retouching process. The list is not exhaustive but will help the conservator in the decision-making about materials. The materials are divided by group´s: aqueous binder solutions, solvent binder solutions, dry solutions and other solutions. MIXING AND MATCHING. A SURVEY OF RETOUCHING MATERIALS Ana Bailão (1,2) | Liliana Cardeira (1) 1. CIEBA, Faculty of Fine Arts, University of Lisbon; Largo da Academia Nacional de Belas Artes nº 14, 1200-005, Lisboa; E-mail address: [email protected] 2. 2. CITAR, Portuguese Catholic University, Centre Regional of Porto; Rua Diogo de Botelho 1327, 4169-005, Porto; E-mail address: ana.bailao@ gmail.com
1. INTRODUCTION It is understood that the term “reintegration” or “retouching” implies on one hand the restitution of parts dismembered in their original place and, on the other hand, the reconstruction of an element from its fragments with the replacement of deteriorated elements or the realization of additions, which provide stability and visual unity to the work being performed. So, the main objectives of reintegration or Keywords Retouching; Retouching survey; Retouching materials. retouching are, therefore, the formal, structural and aesthetic restitution of the cultural heritage [1]. If in the first situation, that of restitution, there is a point of view associated with the union of the original fragments, in the second it is discussed in the sense of introducing new materials, in order to give the object structural and visual uniformity. In both approaches, it is intended to act on the matter that constitutes the object. For reconstruction the conservator need to add materials such as fillers, binders, pigments and varnishes, among others. The retouching process requires good lighting and permanent materials. Conservators are often faced with making difficult decisions regarding appropriate retouching materials for mixing and matching. Ancient and contemporary works of art have different requirements. During the 20th century, there was a vast increase in the variety of materials that artists had access to. Organic and inorganic materials were mixed. It is essential that conservators select retouching materials properly, having in mind the hue, saturation, brightness, texture, smoothness, thickness and refraction index, among other things. There is an innumerable amount of information about retouching materials already available for the conservator [2-5]. However, finding the ones with quality, technical, pros and cons information can require some time and research. The scope of this research is make a survey of the main characteristics and properties of some materials used in the retouching process. For a question of methodology, the materials will Fig. 1 • Image illustrating some of materials for retouching: aqueous binder’s solutions, solvent binder’s solutions and dry solutions. © Ana Bailão.
250 Ana Bailão | Liliana Cardeira be divided in four groups: aqueous binder’s solutions, solvent binder’s solutions, dry solutions and other solutions [Fig. 1]. 1.1 Aqueous binder solutions One of the commonly used materials in the retouching process is the watercolours. They comprise pigments usually bound in Gum Arabic and creates a transparent and luminous layer of paint/retouching. Watercolours are hard to colour match as paint dries, but this characteristic depends of the brand. The brand Schmincke® watercolour, especially Horadam, are one of the glossiest when compared with standard watercolour [6]. A recent example of watercolour is the QoR® watercolour, designed for artists use. The colour strength is achieved by using Aquazol® as binder. This watercolour is being tested due to the fact that conservators have been using Aquazol® since 1990´s. There’s no significant colour change, they are not toxic and have lightfastness pigments. But due their viscosity and bad behaviour with high levels of HR, they are not being used as a retouching material. Also, they can be very glossy. Besides tube watercolour there are other types of watercolour suitable for retouching as watercolour markers. They can be used in specific tasks. These markers are highly pigmented and since they are water-based they provided a permanent ink flow. This characteristic is good for the pointillism technique but did not allow blending or the creation of hues gradation when more than one layer is needed [7]. Gouache is another option material. Comprises pigment bound in Gum Arabic and is distinguishable from watercolour as it has a higher pigment to gum ratio. It also contains extenders as chalk. The colour match is a little more difficult as watercolour because they change the colour and they can become whiter or darker during drying due to the extenders. Gouaches have normally more than two pigments in the mixture with will reduce their permanency and lightfastness [8]. The brand Lascaux have a unique acrylic-modified tempera paint which can be used as a retouching medium. There are 34 hues available. The colours have brilliance and depth and the pigments are lightfastness. The dried film is velvety and elastic but remains water soluble. The paints have covering power and can be applied over a various types of substrates. Water Resoluble Acrylic Medium is another solution provided by Lascaux®. Is colourless. It can be mixed with dry pigments to make pains similar to gouache and watercolours. Dries to a water-soluble film. It can also be used as the first layer on a support to reduce absorbency, thus facilitating subsequent colour washes. Has the capacity of increasing fluidity of paints like gouache and can be thinned to create subtle washes when used with pigments. Used as a binder, more medium produces a watercolour and less medium produces colours with matt and opaque appearance similar to that of tempera or gouache. Another aqueous binder is the JunFunori®, the purified extract from Funori. Funori is a 100% natural dry seaweed polysaccharide, a “red algae” named Gloiopeltis Furcata. The non-purified material has been used by Japanese paper-makers and as adhesive in paper Conservation for decades. In retouching the purified extract is used because is colourless and produce a clear and a very matte retouching medium very useful for monochromatic contemporary art, especially paintings. It can be mixed with pigments. It is very good for mimicking “stained” canvas. For that after preparation Funori can be taken straight from fridge and brushed onto canvas and dabbed pigment into wet medium. Also, lower film of Funori isolates the pigment from the underlying canvas. The glossy can be