80% Cotton / 20% Yak Cotton-Yak is a wool blend composed of 80% cotton and 20% yak wool known for its soft, all-season suitability. Yak wool has excellent heat retention and moisture absorption/release properties, so it is not only warm but also comfortable and does not get stuffy. This wool blend is great for transitional seasons when the climate is more volatile. The waffle pattern is carefully thought out to provide enough breathability while also reserving heat. Ivory: Model is 185cm/6ft1 wearing a size Small. Charcoal: Model is 185cm/6ft1 wearing a size Medium.