Photographs of models wearing beautiful Renaissance masks in San Marco. A transformation mask is a type of mask used by indigenous peoples of the Northwest Coast and Alaska in ritual dances. These masks usually depict an outer, animal visage, which the performer can open by pulling a string to reveal an inner, human face carved in wood. Northwest coast peoples generally use them in pot latches to illustrate myths, while they are used by Alaska natives for shamanic rituals. Normally a mask is an article normally worn on the face, typically for protection, disguise, performance or entertainment. Masks have been used since antiquity for both ceremonial and practical purposes.