THE TREATMENT OF PANELS AT THE INSTITUT ROYAL DU PATRIMOINE ARTISTIQUE, BRUSSELS

At the IRP A most of the paintings on wood which we receive for treatment are of the Flemish School of the fifteenth, sixteenth and seventeenth centuries. The number of panels of other Schools which pass through ~ur hands is very small: a few Italian School, a few icons, a fifteenth century French (Maitre d'Aix), a Catalan altar frontal, two Cranachs. Our experience therefore consists principally in the treatment of supports of Flemish pictures, where the wood used is exclusively oak (except for Flemish paintings done in Italy and Spain). The paintings of this period are often diptychs, triptychs or polyptychs, fixed into a rebated frame which holds them without immobilizing them. The edges of the panels are thinned at the back to form a chamfer or tongue. The planks are joined with butt joints, with or without dowels. The 'Death of the Virgin' by H. van der Goes (Musee Groeninge, Bruges) is an example of a special and so far unique assembly: it consists of tenons set into the thickness of the plank and held by pegs, whose ends are visible on the painted side. Sometimes animal fibres were glued over the joints at the back to consolidate them (e.g. C. de Cater, 'Legend ofSt Rombaut', Cathedral ofSt Rombaut, Malines). The front is smoothed to receive the ground and the paint layer, which also cover the frame. But on the back there are generally cutting marks and surface irregularities on the planks, unless of course the backs are painted, as are the majority of polyptych wings. These panels are thin in relation to their surface area, as the following examples show