Refers to a stitch formation device used in overedge, coverstitch, blindstitch, and buttonsewing machines. Spreaders carry another thread to a position so it can be entered by another stitch forming device. Except for coverstitch machines, a spreader does not have its own source of thread. Spun Kool®: Refers to a spun polyester thread with a flame-retardant finish specifically designed for sewing Children's Sleepwear. For a Textured Polyester thread with the FR Finish, see Tex Kool®.