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- Caracterização através de análise química da escultura portuguesa sobre madeira de produção erudita e de produção popular da época barrocaPublication . Barata, Carolina; Carballo, Jorgelina; Cruz, António João; Coroado, João; Araújo, Maria Eduarda; Mendonça, Maria HelenaMaking use of several analytical techniques, four erudite and four popular Portuguese baroque wooden sculptures were studied. The materials and techniques employed were identified and the relationship between their artistic quality and the materials used was investigated. In general, the pigments were common at the time, but one pigment discovered in the beginning of the 18th century and two rare arsenic pigments were also identified. In popular sculptures cost-saving was detected, particularly concerning the gold leaf. Regarding some technical procedures identified, recommendations found in historical documents did not seem to have been entirely followed, neither in erudite nor in popular sculptures.
- The retable of the chapel of Our Lady of Mercy in the cloister of Oporto’s Cathedral: study, conservation and restorationPublication . Monteiro, Patrícia; Frade, José Carlos; Barata, Carolina; Candeias, AntónioThe retable located in the Chapel of Our Lady of Mercy, in the cloisters of Oporto’s cathedral, dates back to the 17th century. Artistically, it belongs to a transition period between the Mannerism and the Baroque styles. The artistic value and the lack of documented information about the artwork led to the development of a project contemplating its the study. Both chemical and physical analyses - observation of the support, micro-FTIR and SEM-EDS - suggest that the retable was carved in sweet chestnut wood, accordingly to the techniques used at the time. The retable presents water-gilded areas contrasting with blue and red phytomorphic motifs. The polychromed areas were later covered with lead white paint. There were also evidences of previous conservation-restoration interventions. The frail condition of the retable’s materials testified the need to conserve and restore it. Among other procedures, the materials were consolidated and the lacunae were filled and inpainted - partially regenerating the artwork’s aesthetic unity.
- Limitations and obstacles on wood identification from sculptures - analysis of a set of gilded and polychromed flemish artworks from the 15th centuryPublication . Silva, José Luis; Barata, Carolina Sofia; Pissarra, JoséWood identification through its internal anatomy is a complex and time-consuming process, often leading to taxonomic results at genus level (sometimes only family). The identification of the wood support of artworks contains specific methodological requirements and various limitations that are normally not applied with the common histological methodology. Preparation of wood for microscopic examination requires samples with approximately 1 cm3. This is a volume that can conflict with ethical issues of intervention, namely the scale of the piece itself, the aesthetic and structural integrity or even the commercial value of the artwork. Because of these, besides other factors such as the presence of metal leaf, polychromies and varnishes, collecting usually becomes impractical. Also, the absence of any crack, fracture or perforation where collecting could be facilitated, or the presence of degraded or already intervened areas allowed for collecting, all contribute to hamper the identification of wooden artworks. In this paper, which is intended mainly for artwork restorers, we describe the alternatives and solutions that were explored to circumvent the limitations on the wood processing for identification, which allowed us to analyse and characterize a set of Flemish 15th century polychromed and gilded sculptures.
- Retouching scientific photography – the glass plate negatives collection at the Natural History and Science Museum – University of PortoPublication . Pereira, Catarina; Gaspar, Rita; Castro, Laura; Barata, CarolinaThis work presents a part of a research project on retouching gelatin glass plate photographic negatives, its intentions, impact of the practice on the image and object and its current state of conservation. This is a case study on the use of retouching techniques on a scientific collection belonging to the former Dr. Mendes Correia Anthropology Institute, of the Natural History and Science Museum - University of Porto (MHNC-UP). In scientific photography there is a need for a rigorous record and true representation, which sets apart this type of photographic collection from others. Any alterations, such as retouching, should therefore have little or none aesthetic intentions. Retouched negatives were identified in this scientific and academic collection, and allowed to ascertain the purpose of their use and support the need for its preservation.
- Sobre os materiais utilizados na talha da época barroca do noroeste de Portugal - primeiros resultadosPublication . Barata, Carolina; Cruz, António João; Rocha, Fernando TavaresAiming to contribute to the knowledge of Portuguese gilded wood from the Baroque, the first results of a study of 18 retables belonging to Oporto are presented. In order to identify the materials and the techniques used in gesso, bole and gold leaf layers, optical microscopy and scanning electron microscopy were used. Anhydrite and gypsum with low concentration of impurities, bole of good quality and gold alloys with a concentration of gold usually above 90% were identified. The results suggest that recommendations found in historical documents have been followed in the majority of the cases.
- Four reliquary busts from the former monastery of Madre de Deus: Study and conservationPublication . Cunha, Diana; Barata, Carolina; Pais, AlexandreThis article describes the conservation and restoration treatments as well as the historical and analytical study carried out on four reliquary busts from the former Monastery of Madre de Deus, in Lisbon, currently the National Azulejo Museum. These reliquaries belong to a collection composed of forty-five reliquary busts, which represent a unique and practically intact set and has dated busts from the late 16th century until late 17th century. The analytical results obtained suggest that the four busts were produced according to the art treatises of the time and the identified materials meet the materials that would be used in that period.
- Estudo, conservação e restauro de um estojo de faqueiro do século XVIIIPublication . Santos, Alexandra; Barata, Carolina; Subtil, Eulália; Frade, José; Silva, JoséThe intervention of conservation and restoration of an eighteenth century cutlery case and its historical, material and technical study, allowed not only to restore the physical integrity and original function of the case, but also to deepen the knowledge about the materials and constructive system of the storage furniture, which embodies an important testimony of the table etiquette developed in the Portuguese society of the eighteenth century, under the influence of the French court of Louis XIV . This article aims to describe the historical and aesthetical context in which this piece has emerged and its material and technical features based on the results of the laboratorial analysis that were performed.
- The materials and techniques of polychrome baroque wooden sculpture: three works from Baião, Portugal, studied by an integrated, complementary analytical approachPublication . Barata, Carolina; Cruz, António João; Carballo, Jorgelina; Araújo, Maria EduardaThree polychrome wooden sculptures, made between the last quarter of the 17th century and the first half of the 18th century, from a monastery in Northern Portugal, representing an episode of the Passion of Christ, were analysed with three aims: to identify the materials and techniques employed; to clarify the relationship between the three sculptures; to reveal previous restorations. Techniques such as radiography, energy dispersive X-ray spectrometry, optical and polarized light microscopy and Fourier Transform infrared spectroscopy were employed. White lead, vermillion, umber, carbon black, gypsum, anhydride and chalk were identified as pigments and fillers. These materials and the layer structure led to the conclusion that sculptures 1 and 2 were treated as a pair of sculptures and that they underwent at least two restorations: the first was probably done in the workshop where they were made. During the second restoration, the heads were replaced. Sculpture 3 is not restored and its poorer style seems to have correspondence to materials of lower quality.
- Synchrotron X-ray diffraction of bole layers from Portuguese gilded baroque retablesPublication . Barata, Carolina; Rocha, F.; Cruz, A.J.; Andrejkovičová, S.; Reguer, S.Studies based on a scientific approach to materials and techniques used in Portuguese gilded retables from the Baroque are very scarce and focus particularly on works with erudite features and on the characterization of the superficial gold leaf. The conservation and appearance of gilded surfaces, however, depended on the qualities of the clayey ground layer underneath, which is the bole. Colour and texture are closely related to its mineralogical composition. Boles were healing clays. Red to orange varieties could also be used for gilding, usually agglutinated with animal glue when the gold surface was meant to be burnished. Armenian was the name used to identify the best quality material. Microsamples collected from erudite and popular gilded retables, respectively belonging to the city of Oporto and its rural surroundings, were selected for elemental and mineralogical characterization. It was intended to shed light on the characteristics of boles used in Portuguese retables and to understand if there are any differences between materials used in works of distinct artistic quality. Elemental analysis was performed through SEM-EDS. SR-XRD was used for phase identification, performed with a six-circle diffractometer at the DIFFABS beamline of SOLEIL Synchrotron. Portuguese clay standards of identifiable composition and provenance were also analysed. The results suggest that boles are mainly kaolinitic, with variable amounts of illite and smectite. Gypsum was used as an extender. Although the proportions of the main clay minerals are similar in erudite and popular works, in Oporto homogeneity is clearly higher.