Coats Dual Duty Plus Button & Carpet Thread is the heaviest hand sewing thread made of cotton covered polyester. Enjoy hours of pleasurable sewing without fraying. Whether you use it to sew buttons on coats or use it as bindings on rugs, this heavy duty thread is very efficient. Easy to work with, it has a polished glace finish to protect from tangles and abrasion. This is our preferred thread for jersey knit applique in the Alabama Chanin style. Each spool is 50 yards of 75% polyester and 25% cotton thread.