COATS & CLARK-Extra Strong & Upholstery Thread is a heavyweight 100% nylon thread for machine and hand sewing indoor and outdoor heavyweight fabrics. It is a bonded 3-ply nylon thread that is weather, abrasion, and UV resistant. For best results use a size 18 needle and increase stitch length. This package contains two 150yd/137m snap spools of thread. Available in a variety of colors: each sold separately. Imported.