When I made my rag quilt, I also used a layer of cotton for the front, flannel for the batting, and flannel for the backing. I didn't sew the "X" on the individual blocks. The "X" is used when you use batting because the batting is cut smaller than the other fabrics and needs to be held into place. Without the "X" the batting would get all wadded up inside the pocket made by the front and back fabrics. Because the batting layer is flannel and cut the same as the top and bottom, it will be secured in the seams. My rag quilt is washed at least every 2 weeks during the cooler months and it has held up beautifully!