Sulky Leisure Arts LA-4061-I Can't Believe I'm Crocheting King Snap Spool; 60% Nylon (Polyamide)/40% Polyester It does not fuzz, fray or shrink Our small spools are perfect for most projects, but you may want our larger spools for your most loved colors This thread works well in sewing machine and serger loopers Includes one 1000-yard of king spool Strong polyester core wrapped with metallic foil and cross wound spools with snap-end caps Completely washable