This is a 600 yard #50wt 3 ply spool. Designed with award-winning quilter Alex Anderson, MasterPiece is nature's finest thread. Say goodbye to linty cotton threads and the mess they leave in your machine. Specifically created for piecing, MasterPiece creates smooth stitches and holds your fabric together without adding any bulk at the seams. We recommend piecing with a #50 cotton thread, such as MasterPiece, because cotton can be ironed on high heat without the risk of melting. We recommend a Topstitch Sewing Machine Needle, #80/12.