This lustrous 100% silk thread from YLI is our most popular thread with hand applique quilters! 100% pure filament silk means that the entire unbroken strand from the silk cocoon is used in this glossy thread. (No broken or "spun" silk.) This 100 wt very fine thread virtually disappears into the fabric when used, but has the strength and durability for heirloom projects. Snap spools conveniently hold thread ends to avoid unraveling. Nationally known quilter Diane Gaudynski uses this 100 wt silk as a machine quilting thread. YLI 100 wt filament silk thread, 200 Meter Snap Spools, color #231, Schoolbus Yellow.