Yes you can make quilts from old jeans. My SIL has made several, including helping another SIL make quilts for her 4 children out of her DH's old jeans, as a memory quilt. They are heavy, however, she used square patches of jeans, including pockets, with flannel backing, no batting. I can tell you that although heavy, they are nice and warm on cold winter nights. They reminded me of the heavy quilts and blankets I had growing up in a drafty, old house where snow was known to come in the windows if the wind was in a certain direction. Somehow having all those weighty blankets and quilts made me feel snug as a bug on those cold winter nights.