This is another quality of fabric debate. People who know nothing about textiles say one thing, like you shouldn't use sheets, and believe people who want only to makes sales what to buy. You hear if you want to win a contest you must use this or that. No one can give you a good reason not to or to use sheets in quilts. Explore, make pratice pieces. Just be happy with what you do. p.s. 60% of my tops are made with sheets, and my daughter has three times brought me home from Target their house brand which are 100% cotton.