Today was the first day I used Bottom Line Thread in my Bernina 830. It is very picky about the thread I use. I get lots of breakage if it doesn't like the thread. Well, the name should have told me to use it only in the bobbin, but I sometimes don't see the obvious and used it in the top and bottom and my machine loved it. So, I'm using it only now. The 830s are suppose to be such wonderful machines, but I have problems with mine. My old Viking had less problems and cost $7,000 less. Wish I would have known that when I bought the dang thing. It's working fine now with this new thread, so fingers crossed!