CT investigation of two paintings on wood tables by Gentile da Fabriano

A couple of small paintings on wood, property of the National Gallery of Bologna and attributed to Gentile da Fabriano, have been analyzed by means of different diagnostic non-destructive techniques in order to have a complete characterization of their conservation state. Adopted techniques are X-ray fluorescence, infrared reflection imaging, radiography and computed tomography (CT). In this work we will focus mainly on results obtained with CT, which was carried out with a CT system developed by the authors at the Physics Department of the University of Bologna. The CT system has already been used for the full-volume examination of archaeological samples and works of art and mainly consists of a cone-beam X-ray source, a rotational stage for sample manipulation and a Gd2O2S:Tb scintillator screen, optically coupled to a CCD camera. The CT investigation has given us important information on the conservation state of the two tables and on the spatial distribution of the different materials and pigments, besides providing an evidence of a particular technique used by the painter for outlining the figures of the Saint Apostles.