3 90-degree rotations at "difference", for 4 layers total, composite layer created above that, tones inverted, rotated 45 degrees, set to "darken" mode.
Lovely. It would look great as an expensive wool rug on a glowing hardwood floor, don't you think? Also, printed on canvas at about 6'x6' & hanging in a space with a high ceiling & loads of natural light.