I haven't done this myself, but my DSIL cut up old jeans into squares, even using jean pockets as some squares, then backed with flannel and tied. I can tell you they are nice and warm, personal experience. When my brother died, my DSIL helped that DSIL to cut up my brother's jeans, coveralls, etc. and make them into quilts for each of their 4 children, as a memory quilt. gh