I'm making a new duvet for our down comforter. In the past I've used 2 flat king sized sheets, but they don't make printed sheets anymore that I like in 100% cotton. So I'm piecing 2 tops, a different pattern and colors on each side. I'd thought I'd back each with muslin,do some easy quilting to hold those layers together, just to keep the raw edges from rubbing on the comforter, when in use and when it gets washed. The duvet is on the bed by itself in the summer and used as a spread.