Scrutinizing Ecce Homo: European or Indian painting? Assessment by Raman and complementary spectroscopic techniques

Abstract

This work intends to characterize producing techniques and materials used in Ecce Homo painting (P1) from the beginning of the 17th century, made at the time of Iberian Union government in Goa, which belongs to Museum of Christian Art at Old Goa (India). Determination of the manufacturing processes, material characterization of ground/priming layer, and pigment layers were the scopes of this study. Knowledge of Goan painting materials at this epoch is an almost unknown issue. For this study, cross sections were analyzed by micro‐Raman spectroscopy to identify core materials, complemented to other techniques: optical microscopy, Energy Dispersive X‐ray Fluorescence, scanning electron microscopy‐energy dispersive spectroscopy, and micro‐Fourier Transform Infrared spectroscopy. Paintings were also examined by infrared reflectography. By scrutinizing this painting, scientific confirmation on materials and technique was achieved, and the comparison with two other paintings, one Goan (P2) and another Portuguese (P3), from the same period and under the same theme was established. Results allowed identification and origin of paintings under study, considered as a Goan feature by art history, bringing also new data for painting conservation decision making.