Back in the 70's. My first quilt i backed with a sheet. My daughter loved the feel of the sheet her skin on those night she just wanted her quilt. I tried it with yarn. She had it on her bed everyday until the top came apart in the 90's. She took it with her to Rick's collage. It really pleased me that she loved that quilt as much as she did. Last year i went to bb&b got fannel sheets on clearance. Made the quilt using the flat sheet for the back. Then gave my quilt and the fitted sheet as a gift. They loved it. So go for any idea you have. You have nothing to loose.