I just picked up six of these brilliantly colorful pattern paintings on lightweight cardboard and think they are just gorgeous. They are hand numbered in pencil at top center (this one is 5; the highest number of them is 43, so there were once a whole lot of these). My guess is that they were a (well done) art/design school exercise, but at some point, also in pencil, prices ranging from 60 (.60) to 1.75 were added at top right, reiterated with hand-written price stickers on the back...so at least at some point a fair while ago they were offered for sale, which makes me wonder a bit if they were in originally made with that intent? Or were plans/sketches for designs to be painted onto something else?  At any rate, they’re just great looking frame worthy things now, and also stiff enough to just prop somewhere. And the colors—I believe acrylic paint—are even brighter and lusher than photos capture.

This one measures 11” tall x 9 1/4" wide and is in very good condition, with light wear to the board and a little very minor staining.