I am just finishing up a "sorta" string quilt of flannel and didn't use any batting. I started with string in the middle and next couple but my ends were larger. I used one flannel block for the base and it's the backing too. Then I used a variation of QAYG to connect it. It was the first of this that I've tried but was excited to use up my flannel scraps. As mentioned by someone, it does have some bulk in the seams but I'm thinking batting would have just added more bulk in my situation.