If you are thinking you can just "sew" without the knife on a more interior spot on the the fabric, you can't. The knife being disengaged will only leave the edges as is. You would have to have a machine capable of a cover stitch (usually high end machines) to stitch in the open field of a piece of fabric and not cut the edges. I have disabled the knife on some delicate items that I wanted more control, but rolled edges, flate seams, etc. are all benefited by the clean cut the blade makes. Even jeans! Linda