People do use muslin for background piecing, as backing for quilts, wall quilts, table runners,and the list goes on and on. I'm glad you were able to salvage the muslin, although sad about having to go through Hurricane Sandy - I can't imagine. Of course use the muslin, I remember a member of my quilt guild who bought bolts of muslin for hand dyeing her own fabric and wouldn't use anything else. Having a print backing on a quilt makes it two-sided, but in my own experience, I seldom switched over my quilts to use the backing as what you see on top. Use it and I'm glad you got such a terrific bargain - it's meant to be used. I also use a good quality muslin when I make dolls, such as Raggedy Ann, as I feel it makes them look more realistic, plus they are washable, when you put them in a pillow case - trust me I've tried it and it works. Hope your life gets back to a somewhat normal life again. God bless.