Ever since there have been paintings and they have been framed, it is somewhat surprising that no serious research has ever been undertaken on the problem of the frame. To be sure, some scholars have published studies on the different types of frames employed, particularly in Europe during the last centuries; they have classified them according to certain criteria and traced out their variations through various epochs and countries. But the principal question has been avoided: why the frame? Perhaps because it is not capable of being answered; perhaps because located at the limits of esthetics, at the border between painting and furniture, it is considered to have lesser importance in comparison with theories of the visual arts, which have particularly drawn the attention of historians and art critics, not to mention essays full of good will by amateurs in the mood for writing.