Non-destructive techniques used during the restoration of the relief “Madonna and Child” by Jacopo Sansovino

The characterization of the main pigments present in the papier-mâché relief depicting a “Madonna and Child” by Jacopo Sansovino, preserved at the National Museum of Fine Arts in Budapest, has been carried out using non-destructive techniques. In particular, an XRF portable instrument and an XRD apparatus were used in order to determine the elements and compounds of the pigments, respectively. The experimental results indicate that zinc and barium are present on the relief, and this demonstrates that the artwork has undergone restoration since zinc has been in use since 1840 AD. Moreover, radiographic and stereoradiographic analyses were performed several times in order to assess the condition of the work and, above all, the state of the boards that support the work, the cavity inside the cardboard, the surface and the presence of nails