I've been hand quilting long enough that I'm comfortable thinking that I've never had a problem with thread breaking with use. Once in awhile I've used regular sewing thread with no problem. Perhaps the "secret" is in the tension that's being put on the thread while quilting. It should be a bit snug but not tight. I don't knot at the end of the thread either. Just backstitch and run the rest between the layers for about the length of the needle and cut the tail as the needle comes back up. If it's wrong, it seems to work for me!