C&C cotton thread is strong thread but is 3 ply, too thick for me for piecing. It tends to have a lot lint. I use a bigger needle for 3 ply, 90/14 and use it only on my machine that has outside threading. Lint is a killer for machines that have inside threading. Serger thread is not made for piecing, it's too weak when used off one cone for a seam. Three or more cones sewing together makes the surged seam strong. I do like the C&C bobbin thread. It's 80wt and works great for machine quilting on white fabric. It only comes in white.