I am being commissioned to make a T-shirt quilt. I can't get past the word GO. So many places say you have to use interfacing. There is another guru t-shirt quilt maker that says that the interfacing makes it too stiff and hard. I want ti soft but I don't want to get in trouble either with seams rolling and stretching etc. If I could just know for sure what to do I could get started. Looking forward to HELP here.