Boiled Wool

100% Merino Wool stlyes which were boiled/cooked, so the fibres are more dense, keep the body warmth within and can be washed in the washing machine with the wool program. 

Heat, Moisture and friction (all usually taking place in the washing machine) were applied to the fabric already. 

Wool has a self cleaning effect becuase of its scale surface, means you can air clean it. Another way is wrap the product in plastic foil and freeze it for 24 hours. If you dont want any of these inconveniences, just dry clean it professionally.