It depends on the quilt. The quilt I'm currently working on is a whole piece that I had to buy 110 wide. But I didnt want any seams. Normally I just use what have on hand. Ocassionally I will buy a high quality muslin or kona white for backings. I like the scrappy left over backings too, it really just depends on the quilt. I've not done the flannel, or minky.