Vicuña

Vicuna is the finest natural animal fiber in the world, shorn from the wild vicuna of the high Andes, a small undomesticated camelid that yields only a few ounces of usable down each time and can be sheared just once every two or three years. Inca law reserved vicuna cloth for the emperor alone, and the animal was rounded up in communal hunts, shorn, and released. Unregulated hunting after the Spanish conquest drove it nearly to extinction; strict protection since the 1970s has let the herds recover, and the fiber is now harvested under tight controls, making it the rarest and most expensive cloth in the world.