To me knife edge binding is like leaving an opening to turn a sewn project inside out and then you have the opening to close up by folding the edges in and then sewing the opening closed. This is the way I do it all around the quilt. Sometimes I sew a strip of fabric on both sides of the quilt and turn those in. Looks like binding because the fabric is different but not stuffed. I do it differently however the mood strikes when binding.