The only time I've ever used Polar Fleece on a blanket was when I had a piece of jeep cotton and tied it to the fleece for a car blanket---it was REALLY warm. Let some woman borrow it at a very cold cook out and haven't seen it since. Still have some of both fabrics so I guess I'll make another one. I use flannel on baby blankets and on a twin that I made for late MIL while she was in a nursing home. She said that finally she was warm. I used flannel to back Christmas quilts for DD's bed and ours, too hot to sleep under.