Red Heart-Nylon Crochet Thread. The perfect crochet nylon for home decor, apparel, and accessories. Size: 18. Made of 100% Nylon. Putup: 150yd/137m. Recommended Crochet Hook US G6/4mm, recommended knitting needles US6/4mm. Dyelotted: we try but are not always able to match dyelots. Care: Machine wash gentle, no bleach, dry flat. Comes in a variety of colors. Each sold separately. Imported.