I was at a quilt shop a few weeks ago and the girl there said I should use polyester thread to quilt. Well, I only have used cotton since my fabric is all cotton. But I bought a lot of polyester thread because I thought she knew better (working in a quilt shop) and now another gal told me NOT to use polyester thread, that it would rip my cotton fabric. I have all this beautiful polyester thread and I don't know if I should use it or not. Any suggestions?