My 2 cents: there have been more than one discussion on this Board about dryer sheets for foundation piecing and my gut (a large one) feeling is 'don't.' I like to use old cotton sheets for a foundation and endorse others who use paper and then remove it before assembling the sandwich. I don't trust the fragrance and the synthetic material to remain stable for the life of the quilt. BUT I have no proof and many, many quilters do enjoy using them.