Hi Ava, Muslin , which I have used , is the softest fabric you can put on the backing of quilts. Of course, flannel is also good but probably more expensive. Being a frugal yankee, I don't buy much fabric anymore, only when I really have to have something special. Seems the moreI washed the quilt the softer it got. One more thing in favor of muslin, it's plain and won't clash with other fabric. Nice talking with you, Loraine