Aiming 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The results suggest that recommendations found in historical documents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
