THREAD SPOOL: Features one 550 yard spool of Superior Threads So Fine! 50-weight thread made from 3 plies of 100% polyester 100% POLYESTER: So Fine! is an extra smooth all-purpose polyester thread LINT FREE: Due to its' fine lint-free nature and matte-finish, this thread is an excellent blending thread for all types of projects PERFECT FOR CRAFTING: So Fine! threads are excellent for sewing, serging, quilting and for your bobbins MACHINE USAGE: Ideal for all types of quilting and sewing machines