I use Serger thread all the time in mine and have never had a problem. It's also cheaper, I think.

Agree with you !!!

Sorry double post..

I use presencia thread It is by far my favorite as I have no trouble with breakage or bunching. Highly recommend it.

I'm no picky about thread. I buy from Connecting threads, for both piecing and quilting, and I've never had a problem with it. For piecing, I buy it by the cone, which is $10.

My Viking Sapphire 830 works best with Coats and Clarks, the kind with the pull up top that holds the thread end.
I tried Connecting Threads but it did not like it.
C&C is cheaper also.
When I took my machine in for servicing I found out the plastic caps that sit on top of the thread, well Ive been using them upside down, the long end goes inside the thread spool. DUH.

Rose Marie----Don't feel alone. I have a Designer I. Got it used a couple of months ago. I have used those white caps both ways & still don't know which is right. Glad I found out. Really don't know what makes the dif. Seems to work fine either way. Oh, well, live and learn. Dad used to say you're never too old to learn if you're not too d___ dumb. LOL I think he was probably right.

My Viking does great with Atlanta Thread....she doesn't like Connecting Threads at all!
Cotton thread & when they have their sales it runs $1.86 for a 1100 yd spool ($2.95 regular price)
plus they have 700+ colors

http://store.atlantathread.com/gu11yd.html

my designer 1 handles serger thread, I generally use a peice of scrap to test first, just to be sure and let the machine adjust.