A while back, I was carrying extra large prints to complement the 30×40″ framed work on the walls. I built a folding bin from solid oak 1×4″ stock to accommodate these prints. Essentially a three-sided frame, it is hinged on the two back corners, and held open on the front edge with a 1×6″ attached with bedrail hardware from Rockler. Two long 1″ dowel rods are threaded through heavy black canvas duck that has sewn loops to accept the dowels. Both ends of the dowels are drilled to accept a 1/4″ threaded bolt, which attaches the dowel to the short ends of the frame.
In front of the bin is a simple 2×6″, pine, with 1×2″ screwed to the bottom for legs. A strip of 3/4 pine acts as a holding edge on the front. A couple coats of poly on both keep the weather out.