I use sheets all the time, no one but me evens knows as most of mine are gifted to non quilters. Never had a problem. I have a few thrift stores I always stop by to look specifically for sheets, also at garage sales. I rarely spend more than 3.00 for one, very inexpensive backing, more money for fabric. don't tell anyone one but I've been known to cut up a white sheet to use in a top if I am out of white and can't get to a store. In my scrappy series I have been posting some of the white patches are sheeting. Can you tell which or did you notice?