Estudo das formulações proteicas das camadas de preparação de um conjunto de retábulos Portugueses dos séculos XV-XVI por micro-FTIR – uma abordagem quimiométrica

Abstract

The binding media used for the ground layer production of Portuguese paintings from the 15th-16th centuries was studied by μ-FTIR, following a chemometric approach. Principal Component Analysis was restricted to the ester-amide absorption region (1745-1604 cm-1), which proved to be the best spectral window for characterizing ground layer formulations (namely, the binder-gypsum ratio of ground layers). The PCA analysis allowed to discriminate between artists according to some specificities used in the paintings production, as the use of an oil-based layer over the ground layer, probably as a polish impermeabilization layer. This paper, it will be presented the approach and main findings for the paintings studied mostly integrated in Portuguese workshops of Lisboa and Coimbra. 2