I actually love both King Tut and YLI for fmq'ing. So much depends on the machine. I recently upgraded my Janome 7700 to an 8900, and discovered that I was getting thread blobs on the back if I stopped for even a second (a problem I never had with my 7700). I decided to try using Aurifil in the bobbin, and the thread blobs went away, no eyelashes, etc. The variegated threads are to die for!