You might want to try different threads on your machine to find out which one gives you the least trouble with tension and breakage, then stock up on that thread. I have used A&E Perma Core, Tex 30, in my Gammill since I purchased it 15 years ago. It comes in many, many colors. I purchase online from several different places including Kingsmen Quilting Supply, The Quilted Rose and Nustyle at Stover, MO.