Most times I purchase my regular-width backing fabric when I'm purchasing the top fabrics. I usually end up using coordinating, relatively small scale prints. But the last quilt I did was for a HS graduation gift. The top was a softball field using all green; brown; tan batiks. I wanted to try to get the HS colors into the backing and ended up finding a fabulous fabric which incorporated all the colors from the top as well as the school colors I wanted. Stunning fabric.