title: Microscopy and X-ray spectroscopy analyses for assessment of gilding and silvering techniques of Portuguese illuminated manuscripts.
abstract: The objects of this study are various local charters (cartas de foral, in Portuguese) granted by Dom Manuel I, King of Portugal (1495-1521), which substituted for medieval ones and were intended to achieve an administrative unification. These are luxuriously illuminated manuscripts, and our study aims at obtaining a better understanding of the gilding and silvering techniques applied to the parchments, in which the forais were written, between 1500 and 1520. The combined use of microscopy and X-ray spectroscopy analyses allowed us to identify the vestigial materials used for making the parchments, including products such as salt (NaCl), lime (CaO), pumice stone (SiO2+Al2O3), and chalk (CaCO3). Chalk was employed as a whitening agent to give the parchment its final color and opacity. Shell-gold and shell-silver mixed in with animal glue or gum binding media were directly applied on type 1 and 3 forais, while very thin gold leaves (<1 µm) were applied over lead-based tempera grounds (50-180 µm thick) in type 2 forais. Silver was always employed in its finest form without a further protective layer (thus its recursive state of corrosion), while gold was used in various alloy grades.
authors.affiliation: 1Departamento Conservação e Restauro, Faculdade de Ciências e Tecnologia,Universidade Nova de Lisboa,2829-516 Caparica,Portugal.
authors.forename: Agnès
authors.initials: A
authors.lastname: Le Gac
authors.affiliation: 3Instituto Superior Técnico,Instituto de Ciência e Engenharia de Materiais e Superfícies,Av. Rovisco Pais,1049-001 Lisboa,Portugal.
authors.forename: Isabel D
authors.initials: ID
authors.lastname: Nogueira
authors.affiliation: 2Centro de Física Atómica,Universidade de Lisboa,1649-003 Lisboa,Portugal.
authors.forename: Mauro
authors.initials: M
authors.lastname: Guerra
authors.affiliation: 4CITAR-Centro de Investigação em Ciência e Tecnologia das Artes,Escola das Artes,Centro Regional do Porto da Universidade Católica Portuguesa, 1327,4169-005 Porto,Portugal.
authors.forename: José Carlos
authors.initials: JC
authors.lastname: Frade
authors.affiliation: 2Centro de Física Atómica,Universidade de Lisboa,1649-003 Lisboa,Portugal.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Longelin
authors.affiliation: 2Centro de Física Atómica,Universidade de Lisboa,1649-003 Lisboa,Portugal.
authors.forename: Marta
authors.initials: M
authors.lastname: Manso
authors.affiliation: 2Centro de Física Atómica,Universidade de Lisboa,1649-003 Lisboa,Portugal.
authors.forename: Sofia
authors.initials: S
authors.lastname: Pessanha
authors.affiliation: 2Centro de Física Atómica,Universidade de Lisboa,1649-003 Lisboa,Portugal.
authors.forename: Ana Isabel M
authors.initials: AI
authors.lastname: Seruya
authors.affiliation: 2Centro de Física Atómica,Universidade de Lisboa,1649-003 Lisboa,Portugal.
authors.forename: Maria Luisa
authors.initials: ML
authors.lastname: Carvalho
keywords: Illuminated manuscripts