Personally - I would stay far away from Warm and Natural for this quilt. I picked up bamboo at a quilt show and have quilted three quilts using both the straight bamboo batting and 50cotton/50bamboo - it is wonderful and thin but still holds warmth if that is what you want - without being overbearing. flannel is a good choice - I used it in a quilted jacket I made over 25 yrs ago and love - wear it all too often as it is loved & worn - but very comfy! You do need to make sure it is prewashed or you will have a problem with everything puckering when you do wash it later.