Chilkat is the only form of weaving in the world that can weave circular forms. The traditional colours are black, white, blue and yellow - the black most likely made from alder bark - the blue from copper and the yellow from urine & moss. The traditional materials are mountain goat wool and cedar bark. The wool used is usually cleaned, carded. dyed and spun all by hand before the weaving begins. The weaving is also done completely by hand and can take months to years to complete one robe or ritual apron. The woven Chilkat robes are used in rituals and ceremonies and are worn by traditional dancers. Headresses, leg bands, bags, aprons, tunics and robes are all made for use in traditional ceremonies. They usually depict scenes from Native mythology, or the clans' or individual's animal.