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

Tournai, Museum of Fine Arts 677 a. Upper edges of the frames of the wings, with half-dovetails. The tail is flared only to the outside, where the frame is thicker and less weakened by the mouldings. b. The joints at the bottom are through mortise and tenon. We often see this type of joint at the bottom of a frame, coupled with dovetails at the top. c. Two swivel hooks served to close the wings. Only the top one remains, held in place by a modern screw that replaces the old original wrought nail. d. The hinge is placed flat in the small sides of the rails. The blades have flat knuckles, pivoting around a short non-removable pin. a b c d