Estudo do livro de compromisso da Irmandade de Nossa Senhora do Rosário dos Pretos da Matriz de Nossa Senhora do Pilar de Vila Rica (1750) com base em métodos físicos e análise de antigos tratados de pintura

Abstract

Conservation and restoration of Cultural Heritage encompass multidisciplinary knowledge, such as historic documental and scientific analysis. Before any intervention in the Cultural Heritage work it is necessary an a priori technical study, to determine the support, to identify the technique and the employed pictorial material, as well as to evidence the degradation processes that are present in the piece of art in question. Livros de Compromisso das Irmandades Religiosas (Commitment Books of Religious Brotherhoods, free translation), written in the 18th and 19th century in the state of Minas Gerais, Brazil, are cultural assets of great importance. Besides the religious scope, these brotherhoods were patrons of the arts. From the study of the ornamentations in these books, it is possible to investigate some aspects of the cultural and social practices predominant at the time. There are few works on the identification of the dye materials used in the ornamentation of these manuscripts, which result in a lack of data on the production and manipulation of these materials, as well as on the conservation status of these books. Therefore, in the present work historical documentary analyses of one writing manual (5 – Nova Escola para Aprender a Ler, Escrever, e Contar) and seven painting treatises (1 – Il Libro dell’Arte; 2 – Vidas dos Artistas; 3 – Arte da Pintura, Symmetria, E Perspectiva; 4 – Breve Tratado de Iluminação; 6 – The Handmaid to the Arts Teaching; 7 – Segredos Necessarios para os Officios, Artes, e Manufacturas, e para Muitos Objetos Sobre a Economia Domestica and 8 – Breve Tratado de Miniatura) were performed, along with an analysis based on energy dispersive X-ray fluorescence and Raman spectroscopy of the book Compromisso da Irmandade de Nossa Senhora do Rosário dos Pretos da Matriz de Nossa Senhora do Pilar de Vila Rica, written in 1750 and belonging to the Historical Archive of Paróquia do Pilar, in the city of Ouro Preto, Minas Gerais, Brazil. The adornments and miniatures in this manuscript resulted from a detailed and thorough work, and it was possible to identify organic (indigo and carbon black) and inorganic (azurite, iron ochers, vermilion and prussides) dye materials. Through the joint analysis of both scientific techniques used and the documentary analysis, it was also possible to infer the use of organic lakes. The brown dye used in the written parts of the book was made with iron gall ink, while the writings in red were made with vermilion. Pigment mixtures were often employed in the inks used in the miniatures of this manuscript, such as the green color, present throughout the book, which was composed of blue and yellow pigments. Three types of metallic materials were found along the manuscript, namely leaf gold, silver and shell brass, which were applied without Armenian bole as a base for the preparation. In the brass gilding areas, it was possible to visualize green spots due to migration of copper ions. Raman spectroscopy analysis suggests that a mixture of tempera and watercolor painting techniques was employed using egg white, gum Arabic and beeswax as binders. It was also possible to identify several prussides compounds, such as Prussian blue, Berlin green, Berlin white and Na-Prussian white, found mixed in blue, green and purple inks. Besides, evidence of restauration was also found from the identification of copper phthalocyanine, a compound discovered in the 20th century. All the identified materials, except copper phthalocyanine, are in accordance with the descriptions of the eight studied painting treatises from the 15th to 18th century. Analyses of the painting treatises, revealed a great level of polysemy among the pigment’s names, and the determination of their composition was based in the scientific understanding of the inks and materials, combined with a historical analysis of their uses. Our results suggests that the artist was an expert in the techniques of miniature painting. We also demonstrated that the book underwent restoration and demonstrated the relevance of a multidisciplinary approach in the study of Cultural Heritage works.