If you compare the yardage on a spool of Coats and Clark you may find you are spending much more then a spool of the better cotton thread. Coats is made by spinning together lengths of thread pieces from short staple cotton, the cheapest cotton. Look closely at C&C and you will see slubs especially where the ends join. That can cause all matter of tension and stitching problems. Long staple Egyptian cotton is the best and the best manufactured is all one length like Aurifil (Mako) and Superior Masterpiece. There is a legit reason why some thread cost more then others to manufacture for quality. C&C cotton works great in the older vintage machines as that was how thread was made then. Not so much the best for the newer inside threading machines that most have auto tension and other settings.