BAD idea,with the exception of flannel sheets. The percale sheets have a weave that is so tight that when the needle pierces the fabric, it breaks the threads instead of going between them. You end up with holes in your fabric, which weakens it. You also have holds left if you have to re-do any stitches.
I'm of the belief that if you use good fabric (buy it on sale!) on the back, you can turn the quilt over and have two quilts.