I'm working on a large quilt, about 65" x 70" and was going to buy batting, as I'm just about ready to start quilting. Then I remembered I have a queen size flannel sheet I don't need anymore. The thought struck me that I could use that sheet for batting. Anyone done this before? I will be using the quilt to wrap up in on the couch, so it will get quite a bit of use. Having the flannel inside sounds really nice to me. It will be thin, but warm, I think. Any thoughts?