Frames and supports in 15th and 16th-century Southern Netherlandish painting

ASSEMBLY OF PANEL AND FRAME 63 19. Colman 1960, 35-54. The evolution in the jointing of frames that we observe from the late 14th century onwards must be seen in relation to the development of moulded decoration, initially simple and often limited to the inner edge of the frame. The effort is focused on gaining control of mitring, permitting the successful alignment of mouldings that gradually grow in size. This evolution makes it possible to work freely with moulding planes, pushed from one end to the other of the frame members. Mitring was not a novelty. In the panels of The Walcourt Annunciation and Visitation (Namur, PMAA , no. 1 ), a frame is pegged originally to the rear of the panel. 19 The baguette moulding bordering the slats of the frame is mitred. We see the mitre adopted in the Portrait of a Man ( Self Portrait ?) by Jan van Eyck, 1433 (London, The National Gallery, inv. no. NG222) but the uprights, cut into the panel, and the rails, pegged to it are not joined. Major efforts were made to combine mitring with a solid joint. This gave rise in the course of the 15th century to a wide variety of joints, often very complex. In the 16th century, all production centres adopted mitred slotted joints, which combine a mitre with an easy-to-produce open mortise and tenon joint, cut square on the reverse for solidity (fig. 19: 18). D. Pins and pegs Pins (sometimes referred to as dowels) are more or less cylindrical pieces of wood, pointed at the ends, inserted, parallel to the flat side of the panel, in notches provided to that effect in the sides of the components to be assembled. The pins that we have been able to observe on X-radiographs of works from the late 14th century (Namur, PMAA , no. 1 ; Tongeren, BOL , no. 1 ) are wide, in relation to the actual thickness of the supports. Wide in the centre, these pins tapered sharply at the ends. In this way the blocking effect is at the join itself. The thinner panels of the 15th, and especially the 16th centuries, called for finer pins, of more regular shape. It sometimes happened that the thinning of a panel prior to painting brought the pins flush with the surface, with their contours visible in the paint surface. 16th century pins, often exposed by the thinning of the reverse of a panel with a view to cradling, are pointed at the extremities, but are otherwise quite regular. The pins of all periods are polygonal in cross-section. The components of a frame are always pegged together, with rare exceptions. A peg is a small, slightly flared or tapered piece of wood. Forced into the hole pierced into the cheeks of the mortise and into the tenon, it generally sits flush to the two opposite faces of the joint; being forced into the hole from the front, it takes the shape more of the front than of the back of the hole. The pegging is done preferably close to the junction of the parts to limit the effects of shrinkage and prevent the joint opening. Placing pegs obliquely in a straight joint makes it possible to avoid crossing the wood twice along the same thread, thereby minimizing the risk of cracking. In some cases, the hole in the tenon is deliberately shifted slightly towards the join. The dowel is