I don't know about show quilts, but personally I don't see why you couldn't use it. It's fabric and it's 100% cotton. If you don't like it the plain way, you could always dye it, tea or coffee stain it. Slather it around in a bucket of blackberries or blueberries. I bet that would be pretty. Doesn't all fabric start out as muslin before it's dyed anyway??? Just curious.