You usually don't put a backing on a rag quilt. Cut your batting 1" smaller than your starting square. You put the bottom layer of fabric right side DOWN. place your batting square on top, then one or more layers of cotton/flannel right side UP. Sew an "X" thru it, then sew the squares together with a half inch seam. Clip the seams (for 3 quilts you really should look into getting proper rag quilt scissors). Be careful you don't clip your seam. The bottom layer of fabric is the back of your quilt.