I've just discovered my Singer 401 perfers Guterman thread. This came as a huge surprise to me, since Coats and Clark was the only thead my brand mother had available in rual Arkansas during the 50s. Hancocks had C&C on sales, so i bought server spools. As soon as I started using it the thread would break every 5 or 6 in. When I went back to the gutterman, the thread stopped breaking. This leads me to believe that C&C has changed the quality of thread since the good old days. I will save the C&C for hand sewing.