Red Heart-Classic Crochet Thread. The perfect crochet cotton for home decor, apparel, and accessories. Size: 10. Made of 100% Mercerized Cotton. Putup: 1000yd/914m. Recommended Crochet Hook US 7/1.5mm, recommended knitting needles US0-1/2-2.25mm. Dyelotted: we try but are not always able to match dyelots. Care: Machine wash gentle, do not bleach, dry flat. Comes in a variety of colors. Each sold separately. Imported.