YLI Silk Sparkle. Silver. Filament silk plus metallic #100. Great for Quilting when you want lots of stitching in a small space with a little Sparkle. Very thin but, because it's silk, plenty strong enough for machine quilting - even on longarms YLI's regular Silk #100 twisted with one end of metallic. Use it when you want to add just a hint of Sparkle to your quilting.