This is an Akiyoshi Kitaoka design I redrew to use as an op art card front. Makes your head hurt, doesn't it?
The arrangement of small squares is an optical illusion that fools you into thinking the frame is curved. Best from close up. If you move too far away, you can't see the small squares and the illusion disappears.
My first version was woven from strips of black and white paper with the little squares cut out. The illusion was diminished by the very slight offset where the weavers crossed. It was a cool idea, though. I might try it with lighter weight paper and see if it works better.
Extreme Cards and Papercrafting: pop up cards, movable and mechanical cards, digital crafts and unusual papercrafts.