One of the first quilts by boys received was a large flannel quilt with a blanket for batting. The blanket was made of the same material as a soft electric blanket without the cords. The backing the quilter used is the heaviest fabric I've ever held. It's cotton and has laundered well over the years, but I have no idea what kind it is, just very, very heavy. My boys loved it. They were so small they shared a bed then. Now that they are much bigger at 8, 10 and 11, my 11 year old loves it as his weighted blanket. He's austistic and he finds great comfort in very heavy blankets. It's laundered very well over the years and it's had all sorts of abuse happen to it as most baby/kids quilts have.