Do you baste your three layers together on the edge? I have trouble keeping all three layers even and together as I sew on the binding, particularly the backing. I am doing a charity quilt with poly batting that was donated to me. It is much thicker than warm and natural. One other quilt I did, I serged the edge and that solved my problem, but I didn't like all the extra thread that puts there. The one I am working on just now is a tied quilt, therefore it is not quilted right to the edge.