Are you talking about buying the 102 X whatever sheeting fabric on the bolt? I use that all the time. I love the unbleached look and feel of it for hand quilting. They do have it in colors and white white, but I like the slight color variation on the unbleached look when using the patterns of old.
I have used 'sheets' to back my fleece blankets, but I wash and dry them twice to get all the sizing out of them. Then I do a rinse with white vinegar and hang it on the line to dry. I only tie them, I've never tried to quilt them.
Hope all this helps.
Hugs,
Sharon