I wouldn't use any batting. I made a denim rag quilt for my son, backed the denim with sheets, no batting. It was very heavy & warm. If I remember right it was probably 60" x 80" I made it for him to use at the beach when he moved to Ca, after all, who cares if denim gets faded! IMHO I wouldn't use batting or flannel, as flannel is heavy as well.