I use Ecology Cloth which is a higher grade of muslin that I get from New England Quilt Supply. I recently ordered 3 - 40 yd bolts..sold 1 bolt to a friend, and sold 3/4 of another bolt to another quilting buddy and kept one bolt for my cousin and me to use on a vintage looking quilt we're both making ..will use it on the top for the "plain" blocks and also will use for backing..There definitely are different grades so buyer beware..the cheap stuff at Joanns is not what I'd put in a quilt for sure but I have used it in the past to make pillowcase quilt storage pillowcases that I gave to each customer I quilted for. I may use some of the extra I have of the Ecology cloth and whip some of them up..clients loved them..easy and quick with a serger. I always use my Logo stamp to remind them of me..LOL
Anne