Opal is well known for creating yarn for addictive knits and eye-catching socks. The German company donates proceeds from the sale of the Rainforest collection to foundations that save rainforest habitats from development and clear-cutting. Try one or several of these fingering weight, 4-ply yarns that self-pattern as you knit in the round. Size is approximately 465 yards/ 100g ball. 75% superwash wool, 25% nylon. See product page for more details. Fingering weight.