I don't know about the Baby Strings quilt, but I am in the process of doing the seasonal table toppers (nancysnotions.com). The pattern says to piece on paper or muslin. The pattern is too big for me to do the paper (too much bunching at the machine) and I didn't have any muslin on hand. I did have the really thin stiff off white fabric from Walmart that I wouldn't make a quilt out of if my life depended on it. So I traced the pattern on the fabric, sewed the sections on, and it worked perfect. I plan on putting a backing on it, so the thin fabric with the permanent markings on it are just fine. I didn't need the muslin after all. I was very happy to have a use for the Walmart fabric as no one at 2 garage sales would buy it either.