LA CONSERVAZIONE DEI DIPINTI SU TELA: ESPERIENZE E INNOVAZIONI PER DIPINTI DI GRANDI DIMENSIONI

The lining of paintings of very large dimensions can often pose complex conservation problems, but at the same time can provide the impetus for evaluation and modification of 'usual' procedures. The painting laboratories of the Opificio have developed variations and adaptations to both lining techniques and tensioning procedures as a result of experiences with large dimension canvases. The interventions undertaken for the two works by Rubens, damaged in the Uffizi bombing of 1993, Henry IV at the Battle of Ivry and the Entrance of Henry IV into Paris (380×692 cm.) and the large work by Giuseppe Bezzuoli of Giovanni dalle Bande Nere crossing the river Adda (375×592 cm.) required an adaptation of traditional techniques. The problems presented by working on formats of this size were essentially of a practical nature: 1) the difficulty of finding a lining support (traditionally a tight-weave linen canvas) of the dimensions required without resorting to piecing one or more canvases together; 2) the difficulty of keeping both lining canvas and painting in tension because of the problems associated with temporary strainers of the required dimensions undergoing physical deformations during the treatments; 3) the difficulty in keeping interventions and procedures homogeneous while working with the very large staff of technicians needed for paintings of these dimensions. The combination of these considerations directed the restoration staff to find various solutions as regards working procedures and materials. In order to help solve these problems, the conservation technicians at the OPD developed a work surface 800 cm. long with a convex curvature of a maximum height of 6 cm. and a width of 420 cm. The painting positioned facedown on this surface, with the lining canvas positioned above can be tensioned to the sides of the work surface and the lining canvas – also tensioned– is in perfect and constant contact with the original canvas back. This also saved having to resort to any external manual pressure during the lining process. The lining adhesive was again an adaptation of the traditional glue-paste used in Florence. In essence, the basic recipe was modified in order for the adhesive to pass through the looser weave of the adapted linen lining canvas, ('rarola' – commercially available in very large dimensions permitting a single piece of canvas to be used) and adhere perfectly to the original canvas. For this procedure a combined modification of the traditional