Unless I'm using the clear monofilament thread for machine quilting, I only use cotton thread. Lately I've been reading about some of the different threads and weights and plys. The more I read the more unsure of what to use I get. I bought several of the Connecting Threads Essentials thread a while back but it seems to break easily when hand piecing. I've used Mettler Silk Finish 50/2 for piecing over the years but recently read that 3 ply is better for piecing.