The decorative relief, with Spanish influence, is recorded in Portugal from the late seventeenth century, especially in the northern region of the country. This type of work, with a narrative function, acquires in many cases a three-dimensional expression that approaches the sculpture. An example is the polychrome high relief of the side Altarpiece of Nossa Senhora da Graça, of São João Baptista Church, in Foz do Douro. Represents the episode of St. Bento and St. Escolática twins birth, founders of the Benedictine Order. Although there are no documents that allows their accurate dating, the information gathered on the church’s building and some altarpieces hiring, as well as issues of aesthetics order, allows its positing implementation in the first half of the eighteenth century. The conservation condition of the work showed some conditions that endangered their physical integrity, especially at the level of polychrome strata, intending to lead an intervention to propose the preservation of the material and symbolic integrity of the work. It has become clear that the main objective of this study would be the conservation treatment of the work. The intervention took into account degradation factors, opting always for treatments that adapt the environmental characteristics of the space and simultaneously the characteristics of the materials that constitute the relief. The main challenge resided in the chemical cleaning ok the sticky dirt and removal of the oxidized film-forming substances which disturbed the stability of the polychrome layers. In order to contribute to the knowledge of materials and techniques applied in the Portuguese baroque carvings, a technical study, through the identification of its constituents, was undertaken. For such, polychrome samples were collected and analyzed through Optical Microscopy, Micro-FTIR and SEM-EDX, which allowed the identification of the main components of the polychrome layers. The building system is fairly rudimentary and easily understood under close observation. The results showed that the preparation layer is composed of calcium sulphate. The bole layer, known as Armenia (consisting in iron oxides rich clays) was applied beneath the gold leaf. The analysis revealed a gold alloy of high quality. The main pigments identified are consistent with the common pigments used in that period: lead white, vermilion and blue verditer. The FTIR analysis of the samples indicated the presence of a triglyceride indicating the use of an oil as a binder of flesh tones. However, it is not possible to distinguish by this technique which of the siccative oils have been used. Some characteristic decorative techniques were applied, such as estofoado and marbling. Through the obtained results a brief comparison to similar works of the same period was established, providing a starting point for further studies on this typology of works. The fact that this typology is still too poorly explored, from a technical and historicalstylistic point of view, was one of the factors that stimulated this study. In short, this study allowed the preservation of a relief of great artistic interest and also to contribute for the knowledge of the technical features of this type of work.
Date of Award | 26 Jan 2017 |
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Original language | Portuguese |
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Awarding Institution | - Universidade Católica Portuguesa
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Supervisor | Maria Aguiar (Supervisor) & Carolina Barata (Co-Supervisor) |
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- Relief
- Gilded wood
- Polychrome
- Eighteenth Century
- Baroque
- Conservation
- Mestrado em Conservação e Restauro de Bens Culturais
Conservação e restauro do alto-relevo do retábulo de Nossa Senhora da Graça, da Igreja de São João Baptista da Foz do Douro
Soares, I. F. (Student). 26 Jan 2017
Student thesis: Master's Thesis