Polychrome Sculpture Research Articles

Identification of carbon-based black pigments in four South American polychrome wooden sculptures by Raman microscopy

Carbon-based pigments are a group of dark-colored materials, which are classified according to the starting material used and their manufacturing process. Raman spectroscopy is an ideal technique for the identification of carbonaceous matter. Carbon-based pigments show broad bands between 1,300 and 1,600 cm−1 but they differ in position, width and relative intensity, allowing discrimination between them. The aim of the present study was the identification of carbon-based pigments in four polychrome wooden sculptures from the Jesuit Mission La Trinidad in Paraguay. Analysis of the Raman spectral parameters of the polychrome samples and comparison with those of carbon-based pigment references allowed the identification of wood charcoal, lampblack, bistre and a black earth pigment. Complementary analysis by infrared spectroscopy and elemental analysis supported the assignments. In this study we have provided new evidence that Raman microscopy is a powerful technique for the discrimination of carbon-based pigments in works of art. This is the first time that bistre, lampblack and a black earth pigment are identified in colonial art. The chemical information obtained on the black pigments contributed to increase our knowledge on available resources and technology used in the manufacture of the polychrome sculptures at the Jesuit Mission. This information is relevant for our studies on Colonial art.

Polychrome sculptures in Romeo and Juliet and The Winter’s Tale

Since the Reformation, English onlookers have been used to unadorned, unpainted sculptures. However, in The Winter’s Tale, Shakespeare structures the plot around Hermione’s painted statue. Its lifelike appearance serves to enlighten King Leontes about his former tragic errors. Interestingly enough, in Romeo and Juliet, the playwright had already presented the supposedly ‘deadlike’ Juliet as a recumbent statue. So, these two plays may be regarded as part of a diptych as far as the dramatic and aesthetic function of the statue-like female character is concerned. In their reactions when confronted with the coloured “statues” of their beloved, Romeo and Leontes indeed raise several questions as to the role played by the work of art.This article, will first focus on the ambivalence of colour in early modern England so as to analyze the significance of polychrome statues, before turning to the ‘statue scenes’ in both plays in order to highlight their various functions. Finally, I will argue that Romeo and Juliet and The Winter’s Tale should be understood against a complex artistic background, at a time when English artists borrowed their styles from continental and more specifically from Italian sculptures in order to refashion England’s identity.

The use of powdered bismuth in Late Gothic painting and sculpture polychromy

Abstract This paper presents a material study of the altarpiece in the chapel at Křivoklat (Purglitz) Castle called Křivoklat Ark (around 1480–1490), located in Central Bohemia, Czech Republic. The Křivoklat Altarpiece is one of the most important works of Jagiellonian courtly art in Bohemia. It is decorated with polychrome sculptures and panel paintings. An initial investigation of the gilded and silvered parts of the paintings, sculptures and architectural decor of the altarpiece was undertaken using a portable X-ray fluorescence analyser. Not only the expected metallic elements gold and silver were identified, but also bismuth. This surprising result led on to a complex study of the altarpiece, focused on the layered structure and the method by which bismuth was used the paint layers under the metal-coated areas (under the gold and silver plating). The coating technique using bismuth powder in the Late Gothic period has already been described in scientific publications. However, our paper deals with a rare technique, i.e. the use of powdered bismuth in red bole and its plating with gold and silver leaf. Several micro-samples were therefore taken from carefully selected parts of the altarpiece. Only a minimum amount of sample material was taken, due to the significance of altarpiece. The samples were then analyzed with optical and electron microscopy, EDS analysis, micro-XRF, and other methods. The quantitative element mapping on the cross-section of a micro-sample with gilding showed distributions of several elements (Bi, Au, Fe, Al, Ca); this means that the presence of bismuth grains in the red layer under the gilding leaf was proven. Interdisciplinary cooperation and a combination of microscopic and spectral methods have enabled us to describe this unique late Gothic gilding technique, in which metallic bismuth was intentionally used to affect the color scheme of the coated areas in paintings and polychrome sculptures.

Gilt-Teller: uma Nova Ferramenta Multimédia Ao Serviço Da Divulgação Da Ciência Da Conservação

The paper focuses on an innovative bilingual multimedia tool designed within the research project funded by the Portuguese Foundation for Science and Technology (FCT) – Gilt-Teller, an interdisciplinary multiscale study of gilding techniques and materials in Portugal, 1500- 1800. The tool was designed with the help of the company Take the Wind Lda. (Coimbra) and is based on an online platform (www.gilt-teller.pt). It has different components, from documents of general description of the project, its team and outcomes in terms of publica-tions and conference presentation or workshop organization to the historical background of the project and short characterization of the main stylistic epoques considered under study. The three innovative components are: the bilingual glossary on gilding materials and techniques (http://www.gilt-teller.pt/index.php/glossary/index); a movie with the data on laboratory documented reconstructions of gilded composites based on Portuguese recipes (http://www.gilt-teller.pt/index.php/site/historicalReconstructions) and 11 case studies with gilded decoration from the European heritage (http://www.gilt-teller.pt/index.php/site/additionalMaterials).For the first time in Portugal an open access bilingual database including the most representa-tive altarpieces and polychrome sculptures studied within the project was made available to larger and specialized public. For the first time this multimedia tool will bring together knowledge from three different scientific areas, all related with the topic of the project: Art History (with a component of Technical Art History), Conservation and Heritage Science.

Selection of consolidants for the polychrome clay sculptures in the Guanyin Temple, Sichuan, China

Keywords: Polychrome clay sculptures of Guanyin TempleConservation materialsSelectionConsolidationMaterial application關鍵詞 :: 觀音寺彩繪泥塑補塑材料篩選加固材料應用

The long-term stability of a popular heat-seal adhesive for the conservation of painted cultural objects

A large number of products, both natural and synthetic, have been and are used for the consolidation of flaking or fragile paint layers occurring on paintings, polychrome sculpture, furniture and other cultural objects. Most products in use, which include natural as well as synthetic materials, remain untested. Most synthetic materials used for consolidation of paint layers consist of a solution or dispersion of a single polymeric component, and may not have the correct physical and mechanical properties, as they have not been formulated using knowledge and expertise from the field of adhesion science. The only material that has been specifically formulated as an adhesive for the conservation field is BEVA® 371, which contains several components. It was designed as a hot-melt adhesive for the lining of canvas paintings in the early 1970s, but has since then become a popular adhesive for paint layers in need of consolidation. Its stability, an important parameter for this application, was however never fully investigated. This paper investigates the photo-chemical stability of BEVA® 371 as a whole, and each of its components independently using Fourier transform infrared spectroscopy, size exclusion chromatography and solubility tests.

Conserver-restaurer les sculptures polychromées. L’approche déontologique et méthodologique au C2RMF

La filière Sculpture du département Restauration du C2RMF accompagne responsables de collections et restaurateurs libéraux pour la réalisation de restaurations fondamentales de sculptures polychromées. À la fois garante d’une déontologie et d’une méthodologie exposées ici, elle participe ainsi d’une recherche appliquée en conservation-restauration dans un domaine où la notion de réversibilité ne peut être strictement mise en œuvre, en particulier lors d’opérations de dégagement de polychromie.

Témoignage à propos du traitement des sculptures polychromées en France. Une spécialité récente

L’évolution du métier de conservateur-restaurateur de sculptures polychromées est décrite. La conception de la restauration scientifique naît en Allemagne, se poursuit en Belgique et atteint ensuite la France. Les personnalités qui établissent la méthodologie et la déontologie du métier devenu spécifique sont citées. Les difficultés à appliquer ces théories sont soulignées. La naissance des institutions internationales pour la conservation du patrimoine d’une part et des écoles spécialisées d’autre part permettront la diffusion des meilleures pratiques en restauration des sculptures en Europe. L’évolution remarquable des méthodes de laboratoires et de traitement en matière de nettoyage et de dégagement de la polychromie permettent une amélioration très positive du métier et de la protection de ce type d’œuvres d’art au xxie siècle.

Complementary cross-section based protocol of investigation of polychrome samples of a 16th century Moravian Sculpture by optical, vibrational and mass spectrometric techniques

On the occasion of its restoration treatments, the rare medieval polychrome sculpture entitled “The Mourning of Jesus Christ” (16th century, belonging to the Moravian Gallery in Brno, Czech Republic) was subject to a detailed analytical investigation in order to identify the organic and inorganic materials present in the polychrome layers and to map their distribution in the paint structure. This knowledge is extremely useful especially for art objects that suffered reconstructions and/or over paintings or other interventions and can be of help to the restorers in deciding the best conditions and materials for the treatment. In this case, the identification of all components was very important in terms of the assessment of the original painting techniques and discrimination of the presence of over painting layers, being complemented by the study of the construction process and of the history of the artwork. Until recently, the identification of proteinaceous binders contained in small samples taken from polychrome or painted works of art was very complicated and nearly impossible in the case of cross-section analyses. Therefore, the novelty of this paper is the complementary applications of several analytical techniques, such as optical microscopy (OM), nano-LC-ESI-Q-TOF and MALDI-TOF mass spectrometry, microRaman spectroscopy and scanning electron microscopy coupled with energy dispersive X-ray analysis (SEM-EDX) directly on cross-sections. This approach is especially useful for this case as only few samples were available for binder and pigment identification and it allowed the preservation of the samples as cross-sections for further analyses.

Restauration des peintures au plomb par irradiation laser

Lead-containing pigments, which have been widely used in paintings and polychrome sculptures since antiquity, show a specific instability. The pigments alteration often leads to a darkening of the pictorial layer, which is harmful to the aesthetic and understanding of the artworks. No specific restoration technique is available to recover the original color of the discolored paint areas. The thermal properties of lead compounds, however, allow to conceive a method based on continuous-wave laser irradiation of the blackened layer. A set of experimental tests was achieved to optimize the process, and validate the technique in a real situation of a restoration workshop.

Synthesis and fading of eighteenth-century Prussian blue pigments: a combined study by spectroscopic and diffractive techniques using laboratory and synchrotron radiation sources

Prussian blue, a hydrated iron(III) hexacyanoferrate(II) complex, is a synthetic pigment discovered in Berlin in 1704. Because of both its highly intense color and its low cost, Prussian blue was widely used as a pigment in paintings until the 1970s. The early preparative methods were rapidly recognized as a contributory factor in the fading of the pigment, a fading already known by the mid-eighteenth century. Herein two typical eighteenth-century empirical recipes have been reproduced and the resulting pigment analyzed to better understand the reasons for this fading. X-ray absorption and Mössbauer spectroscopy indicated that the early syntheses lead to Prussian blue together with variable amounts of an undesirable iron(III) product. Pair distribution functional analysis confirmed the presence of nanocrystalline ferrihydrite, Fe10O14(OH)2, and also identified the presence of alumina hydrate, Al10O14(OH)2, with a particle size of ∼15 Å. Paint layers prepared from these pigments subjected to accelerated light exposure showed a tendency to turn green, a tendency that was often reported in eighteenth- and nineteenth-century books. The presence of particles of hydrous iron(III) oxides was also observed in a genuine eighteenth-century Prussian blue sample obtained from a polychrome sculpture.

Investigation of the painting materials in Zhongshan Grottoes (Shaanxi, China)

This paper reports on the characterization of paint samples from polychrome sculptures in the main cave of the Zhongshan Grottoes, China. Optical Microscopy (OM), Environmental Scanning Electron Microscopy in combination with Energy Dispersive X-ray analysis (ESEM/EDX), Fourier Transform Infrared spectroscopy (FTIR) and Raman spectroscopy were carried out in order to study the stratigraphy of the sculptural polychromy and to determine the painting materials. Minium Pb3O4 and mercury sulphide HgS, cinnabar or its synthetic form vermilion were found as red pigments. Two mixtures were used to produce a rose color: lead white Pb3 (CO3)2 (OH)2 with minium and hematite added to gypsum. Yellow was attributed to an ochre. The green paint layer has been identified as botallackite [Cu2(OH)3Cl], an isomer of atacamite and paratacamite. Copper oxalate was also found in this green paint layer and calcium oxalate were detected in a numerous of paint layers without restriction to any specific colors. Pigments and their use as mixture or as overlapping different paint layers in Zhongshan Grottoes were identified on a selected number of samples. Over painted areas could be identified and two reasons could explained the blackening of the paintings: a loss of the fragilized colored paint layer, which make the underneath black paint layer visible and a darkening of the upper paint layer, due to the burning of the candles in the temple. Furthermore, FTIR analysis performed on the samples give the indication of an oily binder.

Raman Analysis on 18th Century Painted Wooden Statues

A micro-Raman investigation on four wooden polychrome sculptures of Jan Geernaert (1704-1777), a Flemish sculptor who worked in Italy in the 18th century, is presented. The statues, representing the Holy Virgin Mary, with the infant Jesus in three of them, were created in the period 1750-1770 and are all made by poplar wood. The purpose of the micro-Raman investigations was to identify the original pigments used in 18th century, after later repainting interventions. In all statues, wood is covered by a groundwork, made by gypsum and animal glue. All pigments were identified, both in the original pictorial cover or in later repainted layers. Pigments were spread on a white lead layer (the so called imprimitura). Attention was particularly focused on the blue colours of the Holy Virgin mantle. In the external repainted layers, Prussian blue (Iron(II,III) hexacyanoferrate(II,III)) was found, together with ultramarine blue, a synthetic pigment, alternative to natural precious lapis lazuli, accessible on or after 1828. In one case, phthalocyanine blue is found, confirming a recent (later than 1930-35) restoration. The original skin colours are obtained by white lead and cinnabar (HgS), while the repainted layers are made by mixing chrome yellow (PbCrO4, synthesized in 1809), zinc yellow (ZnCrO4, 1809), red lead (Pb3O4), ultramarine blue, cinnabar, hematite (Fe2O3), goethite (-FeOOH), calcite (CaCO3) and white lead.

Atacamite as a natural pigment in a South American colonial polychrome sculpture from the late XVI century

The image of Our Lady of Copacabana is a gilded polychrome sculpture manufactured in maguey wood at the end of the 16th century. It is a highly devotional image in the Andean region and her sanctuary lays at the shores of the Titicaca Lake in Bolivia. In this study, a green sample taken from the Virgin's veil has been analyzed with the aim to identify the green pigment and the gilding technique. The green pigment layer covered completely the shiny color of the gilded area. First, the cross section of the sample was examined by optical microscopy revealing the presence of green crystals on a white layer; beneath it, a gold leaf on a red bole was observed. Scanning electron microscopy‐energy dispersive spectroscopy analysis allowed the identification and quantification of copper and chloride in the green pigment layer. Analysis by micro‐Raman spectroscopy indicated the presence of atacamite (Cu3Cl2(OH)3) as the green pigment. Although this compound has been identified as a degradation product of copper pigments or of metallic objects containing copper, in this polychrome sculpture, atacamite was used as the green pigment and is identified for the first time as a mineral pigment in a colonial sculpture made in the Viceroyalty of Peru. Copyright © 2012 John Wiley & Sons, Ltd.

Protein identification and localization using mass spectrometry and staining tests in cross-sections of polychrome samples

The identification and localization of the proteinaceous binders are essential issues in studies of painting materials and techniques, for further proposing valid restoration and conservation treatments of the painted or polychrome works of art. The challenge for analytical chemists and conservation scientists is the availability of methods able to simultaneously identify and map the presence of the binders in the multilayered structure of a sample and the possibility to use a very low amount of sample from the studied art object (considering also the criteria of minimum sampling). These methods should be fast, reproducible in different artefacts and in case of mixture of protein-based binders with other non-proteinaceous constituents (oils, resins, waxes, gums etc.) and also economical (both in terms of materials and time consume). In this context, the present paper proposes an innovative protocol of investigation using two complementary techniques – Matrix-Assisted Laser Desorption/Ionisation – Time of Flight Mass Spectrometry (MALDI-TOF MS) and staining tests (one visible and one fluorescent stain) assisted by Optical Microscopy (OM) on cross-section of samples – for the simultaneous identification and mapping of protein – and oil-based binders in paint materials. The novelty is based on the use of MALDI-TOF MS on cross-sections of paints together with a fluorescent stain for protein identification and mapping (mainly used in the area of proteomics) complementing the use of a traditional visible stain for oil-based material identification. The protocol was successfully applied on several samples taken from a Czech medieval polychrome sculpture, entitled “The Mourning of Jesus Christ” (16th century) belonging to the Moravian Gallery (Brno).

XRF, μ-XRD and μ-spectroscopic techniques for revealing the composition and structure of paint layers on polychrome sculptures after multiple restorations

This paper presents the novel application of recently developed analytical techniques to the study of paint layers on sculptures that have been restored/repainted several times across centuries. Analyses were performed using portable XRF, μ-XRD and μ-Raman instruments. Other techniques, such as optical microscopy, SEM-EDX and μ-FTIR, were also used. Pigments and other materials including vermilion, minium, red lac, ivory black, lead white, barium white, zinc white (zincite), titanium white (rutile and anatase), lithopone, gold and brass were detected. Pigments from both ancient and modern times were found due to the different restorations/repaintings carried out. μ-Raman was very useful to characterise some pigments that were difficult to determine by μ-XRD. In some cases, pigments identification was only possible by combining results from the different analytical techniques used in this work. This work is the first article devoted to the study of sculpture cross-section samples using laboratory-made μ-XRD systems.

Non-invasive approach in the study of polychrome terracotta sculptures: employment of the portable XRF to investigate complex stratigraphy

In the field of conservation science, in situ non-invasive analytical techniques are widely used to investigate polychrome surfaces as frescoes, mural or easel paintings. Indeed, these techniques allow achieving information on materials composition and they often reduce the micro-sampling. In this work, in situ non-invasive techniques have been used to study a complex system, terracotta polychrome sculptures. The presence of the priming, the numerous painted layers and the ground layer spread on a porous material substrate are the main features of these sculptures; therefore, their study requires a scientific approach based on results obtained by different analytical techniques. In order to evaluate potentialities and limitations of the non-invasive approach to this complex case, the results of energy-dispersive X-ray fluorescence (EDXRF), spectrophotometry and optical microscopy have been compared with the data achieved by laboratory analytical investigation as optical and scanning electron microscopy, energy-dispersive X-ray microanalysis and Raman spectroscopy. In particular, XRF data collected on several polychrome terracotta are here re-examined on the basis of the results obtained by laboratory techniques. Even if, in some cases, portable XRF may induce to a wrong interpretation of the stratigraphy, it can be considered a suitable instrument for a preliminary diagnostic campaign of terracotta polychrome sculptures. Copyright © 2011 John Wiley & Sons, Ltd.

Terracotta polychrome sculptures examined before and after their conservation work: contributions from non-invasive in situ analytical techniques

The potential of non-invasive in situ analytical techniques such as portable Raman, portable X-ray fluorescence, portable optical microscope and fibre optics reflectance spectroscopy has been shown studying painted layers of Renaissance terracotta polychrome sculptures belonging to the statuary of Santo Sepolcro Church in Milan. The results obtained allowed pointing out the contribution of these techniques to the compositional diagnostic, providing complete information, in some cases, better than micro-destructive techniques, on the kind of pigments used on the external painted layers. Moreover, a comparison with the results obtained before the last conservation work (2009) with micro-destructive techniques allowed ascertaining the removal of the external painted layers during the conservation operations.

Portable XRF study of pigments applied in Juan Hispalense’s 15th century panel painting

AbstractSeveral medieval paintings and polychrome sculptures have been analysed in the frame of a collaboration between the Fine Arts Museum of Seville and the National Centre of Accelerators, dedicated to a non‐destructive study of artworks that belong to the wide museum’s collection. Among the oldest artworks in the collection is the panel painting Archangel St. Michael attributed to Juan Hispalense, one of the first painters in the 15th‐century Seville known by name. The panel was analysed by a portable X‐ray fluorescence (XRF) to get more information about the pigments applied and to identify possible later interventions. The results showed that the pigments were those commonly used in that period. Lead white was found in the preparation of the painting and in colour layers. For yellow colour, yellow ochre was used, while for the red one, the painter usually mixed red earth and vermillion. Blue pigment is azurite, while the copper‐based green one could not be determined more specifically by XRF. Brown colour is made with yellow ochre and organic black or, in some cases, umbra. Black pigment is probably bone or ivory black. Many decorative parts of the panel are gilded, which were confirmed by Au peaks. Later interventions were carried out on the base of Ti–Zn white mixed with earth pigments, while for green areas such as Archangel's wings also chrome green was applied. The research is part of a larger study which is still going on, whose aim is to gain more knowledge about the 15th‐ and 16th‐century Spanish painting and polychromy. Copyright © 2011 John Wiley & Sons, Ltd.

Sacred Spain: art and belief in the Spanish world

The art of Spain and Spanish America during the 17th century is overwhelmingly religious--it was intended to arouse wonder, devotion, and identification. Its forms and meanings are inextricably linked to the beliefs and religious practices of the people for whom it was made. In this groundbreaking book, scholars of art and religion look at new ways to understand the reception of use of these images in the practice of belief. As a result, the book argues for a fundamental reappraisal of the cultural role of the Church based on an analysis of the specific devotional and ritual contexts of Spanish art. Handsomely illustrated essays discuss paintings, polychrome sculptures, metalwork, and books. They call attention to the paradoxical nature of the most characteristic visual forms of Spanish Catholicism: material richness and external display as expressions of internal spirituality, strict doctrinal orthodoxy accompanied by artistic expression of surprising unconventionality, the calculated social projection of new devotional themes, and the divergence of popular religious practices from officially prescribed ones.