I did it back when I started and they were tough to (hand) quilt through. I think it was the sizing. I would not use used sheets, how do you know when they are going to "give"?
When we first started making quilts, many people commented on how nice it was to have printed backing, they were used to seeing muslin I guess. This was in the 1980's. I still get comments on how the quilts are reversible.