I buy it by the yard and at 108" wide. Hancock of Paducah sells it a s well as fabric.com. Shop around for the better price when on sale. I have not seen it at JAF but that doesn't mean they don't carry it. I have just never looked there.

They do make wide width flannel, google it.

I often use flannel as a backing and I have used both flannel sheets and BTY flannel. Reminder, any sheet is usually a lot bigger than the top will be (tucking in room). And, when I buy BTY, I do not like to do a seam down the middle. I prefer to use a full WOF down the middle and the more narrow bits on each side. I find it a bit more interesting. I also tend to 'add' stuff to the backs for interest. Perhaps I will piece a block in the center of each side or do a scrappy 6" strip down the sides of the full piece - anything to add a bit of interest. I also am one of those folks who tend to not prewash my fabric - But - when I am going to do a flannel backing, I do prewash everything.

yes, Joanns carries wide flannel right next to the wide cottons. When you have a 40% coupon, it is a very reasonable option (and no seaming!).

I have bought fabric by the yard from Amazon and Fabric.com I have also found some incredible prices on flannel sheet sets on Amazon. (finding the right color at the right price is the catch there). Recently I had a 30% at Kohls and I found some king size flannel blankets for $23. 90" x 108" is perfect and since they are all season blankets they are basically sheets. I am very happy with them :)

I just keep my eyes out for sales and good deals - - before I need it for a backing

I do like the idea of buying a bolt just so I wouldn't have to worry about it... I might shop around and see what I can find just for fun :)

My experience has been stick to a name brand such as Moda, Robert Kaufman etc. I've bought from JA years ago and the quality is just not the same.

I buy at JA with coupons.