The ones I've seen made have used leftover pieces of batting and jelly rolls that were either imperfect or disliked by the owner. They are a great way to use up all those straggler pieces of batting that refuse to go into the wastebasket. In my spare time I've been cutting "ugly" fabrics into strips for my soon-to-be rug. I used scraps to crochet rugs so I am looking forward to comparing them.