I have been using Moda wide muslin backing for piecing. It has a very nice feel to it. It's $13.99 a yard, but that equivalent to almost 2 1/2 yards of fabric. I grabbed some recently when my LQS has a summer sale at 30% off. I had the cuts done at 1 1/4 yards so I have a pieces 45" by 3 yards.. Most patterns done care if I am cutting what is actually the LOF.
I like the fabric.