2.20 The Evolution of the Technology of Polychrome Sculptures in the Baroque/Rococo Period in Minas Gerais, Brazil

CECOR-Federal University of Brazil
The Getty Conservation Institute

Minas Gerais
Luiz A. C. Souza,Research Fellow-GCI
Dusan C. Stulik
Period of Activity: 2/92 to 1/94

Project Abstract
The captaincy of Minas Gerais, in southeastern Brazil, is located in a region of mountains. It had practically no significance for the Portuguese Crown until the end of the seventeenth century, when pioneer expeditions from the coast, looking for gold, found it in these rivers and mountains.

Following the discovery of gold, the region suddenly experienced a population explosion, and was subjected to strong Portuguese political control. Religious orders and missionary activities were forbidden to develop in Minas Gerais, where the gold was found. This restraint led to the development of third orders of laymen and brotherhoods, which took charge of constructing several Roman Catholic churches in many different areas. The richness of the decoration in the interior of these churches was based on baroque esthetics.

The objective of this research project was to perform a detailed material and technological study of the polychromed sculptures in Minas Gerais, e.g., pigments, binding media, varnishes, glazes, gilding, and silvering, through physicochemical methods of analysis. The project was the experimental part of the Ph.D. in chemistry of L. Souza, working under the supervision of D. Stulik. The researchers brought from Brazil about 550 small samples of sculpture's polychromies, 400 from several sculptures of various museums and cities in Minas Gerais, and 150 from the retables of the Mother Church of Our Lady of Conception, in Catas Altas, Minas Gerais.

The Mother Church of Our Lady of Conception in Catas Altas, Minas Gerais (Brazil), is a magnificent example of the collaborative construction of art monuments by Portuguese and indigenous people. The remarkable fact about this church is that the architectural construction is finished but the internal decoration is not. The unfinished interior allowed us to document and study the different steps for the building up of carving and sculptural works. In the ceiling and also the side altars, there are parts showing just the carved wood, others presenting the wood with the ground, and other parts completely polychromed and finished, showing sgrafitto, gilding, silvering and glazes, etc.

Souza, L. A. C., A. R. Ramos, and C. Avila, "The Mother Church of our Lady of Conception, Minas Gerais, Brazil-The Unfinished Story," Poster presented at the IIC-Conservation of the Iberian and Latin American Cultural Heritage, Madrid, September 9-12, 1992.

ABSTRACT-None available.

Souza, L. A. C., A. R. Ramos, and C. Avila, "The Matriz of Catas Altas, Minas Gerais, Brazil: Techniques, Materials, and Style," Preprints, IIC Conservation of the Iberian and Latin American Cultural Heritage, Madrid, September 9-12, 1992, pp. 154-157.

ABSTRACT-The region of gold deposits in Brazil was discovered by pioneers at the end of the seventeenth century. The richness and the demographic explosion of the new General Mines region (Minas Gerais) gave rise to strong Portuguese political control: religious orders and missionary activities were forbidden there. Consequently, Minas Gerais saw the development of Third Orders and brotherhoods of laymen. The competition between the various religious groups prompted the construction of many churches, the richness of their interior decoration based on the baroque aesthetic. The mother church of Nossa Senhora de Conceição in Catas Altas is a magnificent example of the contribution of both the Portuguese and the indigenous people to the construction of artistic monuments. The church dates from 1738 and the architectural construction is complete but the internal decoration remains unfinished. This made it possible to study the techniques and materials used. In the areas where the ground has been applied but no polychromy, there is a first layer of kaolin followed by a gesso layer. This unusual technique may have been prompted by economy: kaolin is a mineral easily found in the metallurgical zone of Minas Gerais.

Souza, L., "Technology of Colonial Polychrome Sculptures in Brazil," Presentation at the Scientific Program Research Conference, The Getty Conservation Institute, December 16-17, 1992.

ABSTRACT-None available.

Souza, L., "Conservation of Baroque Art in Minas Gerais, Brazil," Presentation at the UCLA Program on Brazil, UCLA Latin American Center, University of California, Los Angeles, February 2, 1993.

ABSTRACT-Discussion on the efforts to retrieve technologies used in the creation of art in the 18th century, and their application to restoration in the 20th century.

Souza, L., "Aspectos Técnicos da Influência Portuguesa e Oriental na Arte Colonial em Minas Gerais, Brazil," Presentation at the 16th Symposium on Portuguese Traditions (Europe, America, Africa, Asia), University of California, Los Angeles, April 24-25. 1993.

ABSTRACT-None available.

Souza, L. A. C., and D. C. Stulik, "Towards a Collection of Brazilian Art Materials," Poster presented at the American Institute of Conservation Annual Meeting, Denver, Colorado, June 1993.

ABSTRACT-None available.

Souza, L. A. C., and D. C. Stulik, "Red, Green, and Yellow/Brown Glazes on Baroque and Rococo Polychromed Sculptures from Minas Gerais, Brazil," Poster presented at the ICOM-CC 10th Triennial Meeting, Washington, D. C., August 22-27, 1993.

ABSTRACT-Presents some of the recent findings concerning the use of glazes on gilding and silvering surfaces of wooden polychromed sculptures. These preliminary results are part of a major research project designed to study the evolution of the technology of baroque and rococo polychromed sculptures in Minas Gerais. The methodology includes historic research and scientific analytical techniques such as FTIR, PLM, UV/VIS spectroscopy, SEM, and GC/MS in order to identify the materials and techniques used in Minas during the eighteenth century. The focus of study is primarily on the Mother Church of Our Lady of Conception in Catas Altas, Minas Gerais, because its internal decoration is incomplete and the church has never been restored, allowing access to all original materials and techniques dating back to 1738.

Souza, L. A. C., and M. R. Derrick, "The Use of FT-IR Spectrometry for the Identification and Characterization of Gesso-Glue Grounds in Wooden Polychromed Sculptures and Panel Paintings," Materials Issues in Art and Archaeology IV, Vol. 352, Symposium held May 16-21, 1994, Cancun, Mexico, Materials Research Society, Pittsburgh, Pennsylvania, 1995, pp. 573-578.

ABSTRACT - Traditional western techniques for gilding of polychrome sculptures and panel paintings include the use of grounds prepared by the application of a first layer of gesso grosso followed by a gesso sottile layer, as described by Cennino Cennini in his treatise on painting techniques. These techniques were used in Italy since the middle ages, and were later adopted by many artists in the new world in the regions under Spanish and Portuguese (Brazil) rule, sometimes with local variations in the materials and techniques.

This paper discusses the use of FT-IR spectroscopy for the identification of inorganic materials present in the grounds of baroque wooden polychromed sculptures from Minas Gerais, Brazil. This technique allows the quantitative analysis of the separate layers of the grounds, with respect to the anhydrite/gypsum ratio present in the sample. The techniques has several advantages over the one currently used (Debye-Scherrer chamber for powder X-Ray diffraction). FT-IR spectra can be obtained in a few minutes allowing quantitative quantitative results, while XRD usually takes more time and does not give accurate data for quantitative studies. The paper also discusses the results of the studies of the grounds in Brazilian polychromed sculptures and compares the original Italian technique with Portuguese and Spanish techniques and its variations in Brazil.