Science Applied to Modern Mural Painting Studies. Traditional Pigments and Innovations in Almada Negreiros’ Working Palettes at the DN Building in Lisbon (Phase 2)

Abstract

This chapter reports the analytical study carried out on Almada Negreiros’ two working palettes in the public hall of the DN Building in 1939. Both palettes were hidden behind wooden cabinets and discovered in 1991 during conservation works. The first study carried out in 2021 focused on the identification of cadmium pigments. In phase 2, the goal was to extend the research to other colour materials to ascertain the different types of pigments employed by the artist. The analytical setup comprised in loco colorimetry and spectrophotometry in the visible range, h-OM and h-EDXRF, complemented by OMVis and μ-FTIR of micro samples collected from the paint layers. The data obtained were compared with the results of the analyses carried out in the pigments found in powder form at Almada’s studio from the commercial brand Pigments pour la Fresque-LeFranc-Paris, as they are the most likely source of the colour materials used in the production of the working palettes. This research highlights not only the use of traditional pigments commonly found in fresco palettes, such as earth pigments, but also the introduction of modern colourants produced in the 19th century onwards. These are the case of the Cd pigments, Cr green pigments, cobalt and ultramarine blues and, most likely, Mars colours.