leaves
A term formerly applied to window-shutters, the folding-doors of closets, &c., especially to those of the almeries and the repositories of reliques, formerly so numerous in churches: some pieces of sacred sculpture and paintings also were protected by light folding-doors or leaves, particularly those over altars, and the insides of the leaves themselves were often painted, so that when turned back they formed part of the general subject… (Parker, 1896)