Red Heart-Fine Crochet Thread. The perfect crochet cotton for home decor apparel and accessories. Size: 20. Made of 100% Mercerized Cotton. Putup: 400yd/365m. Recommended Crochet Hook US 10/1mm. 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.