  In this work we present a modification to conventional X-rays fluorescence
using electrons as excitation source, and compare it with the traditional X-ray
excitation for the study of pigments. For this purpose we have constructed a
laser-based source capable to produce X-rays as well as electrons. Because of
the large penetration depth of X-rays, the collected fluorescence signal is a
combination of several material layers of the artwork under study. However
electrons are stopped in the first layers allowing therefore a more superficial
analysis. We show that the combination of both excitation sources can provide
extremely valuable information about the structure of the artwork.
