Brilliantly reflective Sulky Holoshimmer Metallic thread is a thin, flat, ribbon-like, holographic foil that is laminated with polyester, which makes it amazingly reflective so you can add the ultimate sparkle to all of your decorative projects. This metallic thread works perfectly on sewing, serging, and knitting machines, and for handwork. It does not fuzz, fray or shrink. Made of nylon and polyester, 40wt and includes 250 yards. Use sewing machine needle size 90/14.