Technical non-invasive study of the novo-hispanic painting the Pentecost by Baltasar de Echave Orio by spectroscopic techniques and hyperspectral imaging: In quest for the painter's hand.

This paper presents a combination of noninvasive techniques for the study of superimposed painting stages in The Pentecost, a Mexican Colonial panel painting attributed to Baltasar de Echave Orio (1558 - 1619). The application of reflected hyperspectral imaging (HSI) analysis for mapping the distribution of the pigments in the paint surface and the use of ultraviolet (UV) fluorescence photography and X-ray radiography as complementary imaging techniques provide new insights into the making process of the artwork, its manufacturing and conservation state. For a better understanding of the in situ results gathered, we studied a series of paint mock-up samples created following recipes and studio practices from art treatises. The use of spot analytical methods such as fiber optic reflectance spectroscopy (FORS) and X-ray fluorescence spectroscopy (XRF) allowed for a robust identification of the artist's materials.