This stitch, if done correctly, is great and holds extremely well in all kinds of heavy uses. I like to use a double thread of crochet cotton with extra loft poly batting. Gives the look of a comforter. As far as a knot is concerned, all you have to do is have a long tail, because the first stitch locks the thread as would a knot. For tying off, you can either leave a long tail in between the layers, or make a small knot in the last stitch and then leave a tail. Either way it works well.