At virtually two times the toughness of rayon thread, Isacord is the smoothest and most trustworthy polyester thread created. It has been crafted from the finest resources to offer the correct amount of flexibility to permit fast running without knotting or tightening while preventing thread breaks. 1,000 meter mini-king spools have a one-of-a-kind snap in base for tidy and simple storage. Offered in 423 great shades. At virtually two times the toughness of rayon thread, Isacord is the smoothest and most trustworthy polyester thread created. It has been crafted from the finest resources to offer the correct amount of flexibility to permit fast running without knotting or tightening while preventing thread breaks. 1,000 meter mini-king spools have a one-of-a-kind snap in base for tidy and simple storage. Offered in 423 great shades.