Seralene is a 100% Polyester Overlock thread that is perfect for creating fine, almost invisible seams on light weight fabrics. Thanks to its fine qualities, Seralene is suitable for high quality basting as well as for invisible stitching and decorative work. It also makes an ideal underthread or looper thread. Shrinkproof & easy to clean. Recommended needle size: 70-80. 2000m/2187yds per spool.