Most shoe soles are so boring. Shoes that are not athletic or used in slippery conditions should have nifty treads on the soles. I drew a few treads that I thought would be more interesting than the usual lines, triangles, and rectangles. I added some circles and spirals because I read that they are the best shape to shed water and make soles less slick. I may try and make some for a pair of old shoes.
