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

CHAPTER X 212 Fig. 109. The shadow of the frames is painted in trompe-l’œil at two locations in the upper altarpiece: Adam/Eve and the Annunciation. On the Adam and Eve panels, the painted shadow is to be interpreted as an instruction for opening these wings at right angles to the wings of the angels, and perpendicular to the window. In the Annunciation, the shadow is cast obliquely on the floor of each of the four compartments, which indicates that the ensemble is intended to be closed flat.