A clamp adapted to retain paintings which includes a female piece rotatably connected to a male piece. The proximal end of the female piece includes a sloped locking shoulder which engages a distally extending horizontal flange in the proximal end of the male piece in order to lock the clamp.

A clamp adapted to retain paintings which includes a female piece rotatably connected to a male piece. The proximal end of the female piece includes a sloped locking shoulder which engages a distally extending horizontal flange in the proximal end of the male piece in order to lock the clamp.