A non invasive method to detect stratigraphy, thicknesses and pigment concentration of pictorial multilayers based on EDXRF and vis-RS: in situ applications

Energy dispersive XRF analysis (EDXRF) in association with visible reflectance spectroscopy (vis-RS), both achieved by portable instruments, can be successfully applied, in a wide range of cases, to investigate wood or canvas paintings in order to obtain some stratigraphic information with non-invasive techniques. The specific aim of this work is to use them as quantitative tools: EDXRF to reconstruct the thicknesses of the detected layers, vis-RS to report pigment concentration in the uppermost layer. We present here some in situ analyses of famous paintings by Andrea Mantegna and Giovanni Bellini, compared with stratigraphic optical microscopy observations on cross sections. Advantages and limits are pointed out. (orig.)