Keep in mind that sweats are a knit and stretch, your cotton pieced top won't, could cause problems. I usually end up creating my own problems that I didn't foresee - I don't need to start with incompatibility in fabric, but that's just me! Good luck with whatever you choose. Might want to do a sample on say a sweat sleeve and a piece of cotton to see how it works. Be sure to let us all know. Patty