I was only using King Tut on my Tin Lizzie, but when talking to the service person last week, he said I could use any quilting thread and just make sure the tension is adjusted. I used Coats and Clarks today and it did fine (had So Fine in the bobbin).

At one time I was able to use CT on my long arm(Voyager 17), but for some reason, it took a dislike to it, and neither I or the service tech could figure out why. I now use Maxi-Lock serger thread with no problem. Go figure......