The mask is an object worn over or in front of the face to hide the identity of a person and by its own features to establish another being. This essential characteristic of hiding and revealing personalities or moods is common to all masks. As cultural objects they have been used throughout the world in all periods since the Stone Age and have been as varied in appearance as in their use and symbolism.
Masks have been designed in innumerable varieties, from the simplest of crude "false faces" held by a handle to complete head coverings with ingenious movable parts and hidden faces. Mask makers have shown great resourcefulness in selecting and combining available materials. Among the substances utilized are woods, metals, shells, fibers, ivory, clay, horn, stone, feathers, leather, furs, paper, cloth, and corn husks. Surface treatments have ranged from rugged simplicity to intricate carving and from polished woods and mosaics to gaudy adornments. The morphological elements of the mask are with few exceptions derived from natural forms. Masks with human features are classified as anthropomorphic and those with animal characteristics as theriomorphic. Masks usually represent supernatural beings, ancestors, and fanciful or imagined figures, and can also be portraits. The localization of a particular spirit in a specific mask is often a highly significant reason for its existence.
The change in identity of the wearer for that of the mask is vital, for if the spirit represented does not reside in the image of the mask, the ritual petitions, supplications, and offerings made to it would be ineffectual and meaningless. The mask, therefore, most often functions as a means of contact with various spirit powers, thereby protecting against the unknown forces of the universe by prevailing upon their potential beneficence in all matters relative to life.
Masks have traditionally been made by professionals who were either expert in this particular craft or were noted sculptors or artisans. In societies in which masks of supernatural beings have played a significant ceremonial role, it is presumed that the spirit power of the created image usually is strongly felt by the artist. A primary belief involved in both the conception and the rendering of these objects was that spirit power dwelled in all organic and inorganic matter, and therefore the mask will contain the spirit power of whatever material was used to make it. This power is considered a volatile, active force that is surrounded by various taboos and restrictions for the protection of those handling it. Certain prescribed rituals frequently have to be followed in the process of the mask's creation. A spirit power is also often believed to inhabit the artist's tools so that even these have to be handled in a prescribed manner. As the form of the mask develops it is usually believed to acquire power increasingly in its own right, and again various procedures are prescribed to protect the craftsman and to ensure the potency of the object. If all the conventions have been adhered to, the completed mask, when worn or displayed, is regarded as an object suffused with great supernatural or spirit power. In some cultures it is believed that because of the close association between the mask maker and the spirit of the mask, the artist absorbs some of its magic power.
The wearer is also considered to be in direct association with the spirit force of the mask and is consequently exposed to like personal danger of being affected by it. For his protection, the wearer, like the mask maker, is required to follow certain sanctioned procedures in his use of the mask. In some respects, he plays the role of an actor in cooperation or collaboration with the mask. Without his performing dance and posturing routines, which are often accompanied with music, the mask would remain a representation without a full life-force. Upon donning the mask, the wearer sometimes undergoes a psychic change and as in a trance assumes the spirit character depicted by the mask. Usually, however, the wearer skillfully becomes a "partner" of the character he is impersonating, giving to the mask not only an important spark of vitality by the light flashing from his own eyes, but also bringing the character alive by his movements and poses.
Among Oceanic peoples, North American Indians, and various tribes of Africa, certain times of the year are set aside to honour spirits or ancestors. Among nonliterate peoples who cannot record their own histories, masked rituals act as an important link between past and present, giving a sense of historic continuity that strengthens their social bond. On these occasions, masks that are recognizable as dead chieftains, relatives, friends, or even foes are worn or exhibited. Gifts are made to the spirits incarnated in the masks, while in other instances dancers wearing stylized mourning masks perform the prescribed ceremony. In western Melanesia, the ancestral ceremonial mask occurs in a great variety of forms and materials. The Sepik River area in north central New Guinea is the source of an extremely rich array of these mask forms mostly carved in wood, ranging from small faces to large fantastic forms with a variety of appendages affixed to the wood, including shell, fiber, animal skins, seed, flowers, and feathers. These masks are highly polychromed with earth colours of red and yellow, lime white, and charcoal black. They often represent supernatural spirits as well as ancestors and therefore have both a religious and a social significance.
Rituals, often nocturnal, by members of secret societies wearing ancestor masks are reminders of the ancient sanction of their conduct. In many cultures, these masked ceremonials are intended to prevent miscreant acts and to maintain the circumscribed activities of the tribe. Members of secret societies often also conduct the rituals of initiation, when a young man is instructed in his future role as an adult. Totem and spiritualistic masks are donned by the elders at these ceremonies. In western and central Congo (Kinshasa), in Africa, large, colourful helmetlike masks are used as a masquerading device when the youth emerges from the initiation area and is introduced to the villagers as an adult of the tribe. After a lengthy ordeal of teaching and initiation rites, for instance, a youth of the Pende tribe appears in a distinctive colourful mask indicative of his new role as an adult. The mask is later cast aside and replaced by a small ivory duplicate, worn as a charm against misfortune and as a symbol of his manhood.