I use BottomLine in the bobbin for most of my quilting. I use whatever gives me the effect I am looking for on top. I have used Aurifil, various brands of metallics, invisible polyester, Isacord, Floriani, and my favorites SoFine and King Tut. I just make sure to check the tension balance on a sandwich scrap before I start and adjust as needed. You limit yourself too much if you only use one yep of thread.