The analysis of a Portuguese "papier-mâché" sculpture depicting Saint Anthony is presented in this case study. Several questions were addressed such as the characteristics of the support, pigments used, and artistic technique in order to establish a possible timeline for its production. Qualitative analyses of the cross-sections and of the paper support were performed by optical microscopy using reflected light. Two polychrome layers from different periods and a rag pulped support were identified on the sculpture. The use of micro X-ray fluorescence and Raman microscopy techniques enabled the differentiation of coloring materials used in both polychromies. Semi-quantitative analyses of the gilded samples were also performed by scanning electron microscopy in combination with energy-dispersive spectroscopy allowing the determination of a common Au-Ag-Cu alloy with differences in the purity of the gold. The identified coloring materials lead us to believe that the sculpture was produced in the 19th century, being overpainted in the first half of the 20th century.

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Extended abstract of a paper presented at Microscopy and Microanalysis 2011 in Nashville, Tennessee, USA, August 7–August 11, 2011.

El trabajo aquí desarrollado pretende ofrecer una nueva perspectiva para el estudio de los retablos Barrocos portugueses, incidiendo en la caracterización elemental del oro utilizado para el dorado y en la identificación de elementos característicos de su composición. En este sentido fueron analizados los retablos mayores de las iglesias de San Bento da Vitória, Santa Clara y San Francisco, localizados en la ciudad de Oporto. Los análisis cualitativos y semi cuantitativos fueron efectuados por microscopía óptica (OM) y microscopía electrónica de barrido con difracción de rayos X (SEM-EDS). El análisis de los resultados permitió identificar una aleación de oro/plata/cobre y la presencia de oro de gran pureza, entre 22 y 23 quilates.

"Papier-mâché" is a term which has been applied to three-dimensional objects having a paper core [1, 2]. In Portugal there are very few examples of paper objects either in architectural decoration or in isolated objects such as sculptures [3]. The studied sculpture was an opportunity to learn more about a rather unknown and rare art form. Several questions were addressed such as the study of the support and pigments in order to establish a possible timeline for its production. For these purposes samples from the sculpture were observed under microscope and analyzed by the complementary micro X-ray Fluorescence ( -XRF) and Raman techniques. The number of samples obtained from the sculpture was limited to its state of conservation. Observation of cross-sections under microscope revealed two polychrome layers, most likely from different periods. These layers often present the same color palette, nevertheless the use of -XRF and Raman techniques enabled the differentiation of coloring materials used in both polychromies. The cross-section analysis of the flesh-tones also revealed the presence of two layers with similar colour. Both were achieved admixing zinc white and vermillion pigments. The presence of lead white -only found in the pink overpaintallowed the distinction of the two layers. The original brown color of the tunic consisted on iron and manganese based pigment, likely umber while the brown overpaint was obtained admixing vermilion, carbon black and calcium carbonate pigments. Elemental mapping obtained using XRF technique revealed similar gilding techniques layers (Fig. 2): the gold leaf was applied on a red iron based layer, likely red ochre. Brown coloring material was then applied over the gold and then carefully scrapped in order to let the gold visible and to create different patterns like the texture of the tunic or the leaf decoration in the lower part of the vest -"estofado" technique. Raman technique revealed the use of calcium carbonate in the ground layer of both polychromies and among paper fibers, possibly used as paper filler [4]. Paper fibers were examined with an optical microscope and were identified as textiles fibers. The identified coloring materials lead us to believe that the sculpture was produced out in the 19 th century, being overpainted in the first half of 20 th century [5]. This conclusion is based on the identification in both polychromies of zinc white, which is a pigment that was only manufactured throughout Europe after 1850. Furthermore the fasten decrease of vermillion use after the manufacture of cadmium red after 1919 leads us to believe that the overpaint layer is from late 19 th or beginning of the 20 th century.

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The Nativity scene (presépio), from the Santuário de Nossa Senhora dos Remédios, in Lamego (Portugal), is a rare and precious example of Portuguese clay sculpture from the eighteenth century. This Nativity scene presents more than 60 polychrome clay sculptures, with heights between 10 and 18 cm. The main figures show rich details and techniques, similar to the wooden sculpture decorative motives from the same century: glass eyes, lace, sequins, silver halos, glazes and metallic leafs. The presépio is contained within a wooden polychrome structure -a reliquary. Several analytical techniques were carried out in order to characterise some of the physical and chemical features of the materials. The qualitative and semi-quantitative analyses of the pigments were performed by optical microscopy and by scanning electron microscopy coupled with energy dispersive X-ray spectrometry. The technical investigation preceded the conservation and restoration of the sculptures. ResumoO presépio em barro pertencente ao Santuário de Nossa Senhora dos Remédios, em Lamego (Portugal), é um precioso exemplar da escultura portuguesa em barro do século XVIII. O conjunto é composto por mais de 60 esculturas em barro policromado, com alturas entre os 10 e os 18 cm. As principais figuras evidenciam pormenores e técnicas semelhantes à escultura em madeira do mesmo período: olhos de vidro, rendas, lantejoulas, coroas, vernizes e aplicação de folha metálica. O presépio encontra-se numa maquineta em madeira. Foram efectuados diversos exames laboratoriais de forma a permitir uma caracterização física e química dos materiais e a análise tecnológica do conjunto. A análise qualitativa e semi-quantitativa dos pigmentos foi realizada por microscopia óptica e por microscopia electrónica de varrimento com espectrometria de raios X por dispersão de energia. O estudo tecnológico precedeu a intervenção de conservação e restauro do conjunto.Conservar Património 20 (2014) 65-73 |

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