Through many washings the 100% cotton block has shrunk a tiny bit and the backing hasn't so it doesn't lay flat any more. I think I will take the back off and put on a new one of 100% cotton.
Cathi has made a similar block and showed her progress the last few days and it reminded me how much I enjoyed working with this block. The traditional name for my block is Carpenter's Wheel which is made with diamond pieces. A similar block made with half square triangles is called Dutch Rose.