26 weight, 2 ply textured "wooly-like" polyester thread that’s available in 36 solid colors. Polyarn is a replacement for similar nylon threads and was designed specifically for serger sewing and overlock stitching. It has excellent stretch and doesn't yellow or go brittle over time like nylon threads. Polyarn is a top choice for sewing garments, simple hems, or fancy stitches. For needle usage, we recommend loopers.