Just did this recently for an oversize twin quilt and had no issues. I pre wash all my fabrics. Didn't have any more issues with threads/strings on the flannel than the regular cotton. I don't have a walking foot but had no issues when sewing the binding down to the entire quilt. I machine sew my binding to the front then hand sew to the back. I think the flannel was actually easier as a backing during the machine sewing phase since it slides easier than the regular cotton. The flannel I used was a nice heavy flannel by Moda. Would definitely recommend this fabric.