I just used 7 in blocks of cotton on front and back and flannel in the center. I cut all three blocks the same size and used a 1/2 in seam. They really go together quickly. I recently came across a great find. My brother works for a laundry service and when they have towels or flannel sheets that have a small stain or hole in them they let their employees take them home. He just brought me 10 full size flannel sheets. I'm going to use those on my next rag quilts. It will save a lot of money and they are already preshrunk. Can't bet that.