I have 2 Bernina's...a 930 & a Artista 200E. I use all types of thread....regular/embroidery/metallic/heavy carpet/etc. I've bought cheap thread & expensive thread. Once in a while you'll get a spool that's junk/a lemon. If I get one that wants to fray/break I unwind some, change needle & try again. If it still gives me trouble I toss it. Thread is like anything else....now & then you get a lemon :(.