Abstract: A jig for assembling a frame. The jig may be for woodworking and the frame may be for a picture. The jig comprises a top plate having a first and second opening. The top plate also contains an elongated slot. A bottom plate is laterally arranged below the top plate. The bottom plate contains a third and fourth opening. The bottom plate also contains an aligned elongated slot. A first guide bar and second guide bar are disposed through the openings in the plates, and fastener members, operatively associated with the first and second guide bar, is included for fastening the top plate and the bottom plate together. The jig may further comprise a guide member disposed between the top and bottom plate. The guide member has a first and second side that form a right angle so that the two inserted pieces of wood stock of the frame form a ninety degree corner.