Well, I use Joannes coupons for 40 to 50% off one cut of fabric and get the 90" wide good smooth muslin....I have a hard time putting large pieces of lovely fabric on the back of quilts when I could use it for another quilt top. With 90" wide muslin I usually don't have to worry about piecing the back....if I do use regular fabric I seam it together with about a 1" seam----then snip into the selvage every 3 to 4 inches.....works for me and what I was taught by another quilter.