Misha and PuffStudio Misha & Puff yarns are certified by the Responsible Wool Standard. The Responsible Wool Standard (RWS) ensures the ranches, farms, transporters, and everyone along the production chain meets a stringent standard of care for their animals. When you sit down to knit with RWS wool yarn, you can be confident the sheep who provided you their winter woolies have been treated with the quality care and respect they deserve. Worsted Weight 100%