Royale Extra Fine Crochet Cotton. Extra Fine crochet thread for fine crochet work; such as doilies; table runners; home decor and accessories. 100% Mercerized Cotton; 3 ply; size 30; 500yd/457m. Suggested crochet hook: 12/0.75mm. Care: machine wash (max.temp. 104F/40C); dry flat; do not bleach; iron low; do not dry clean. Imported.