Masks are usually worn to disguise one's identity by hiding the face. They are used for ceremonial and practical purpose. Some of masks are made for protection of workers and sportsman, others for performances and entertainment. Sometimes masks are used in criminal activities, but most the time the practical purpose is harmless.
The painting above shows a modern version of the classical Venetian Mask.
The masks are often white, some are gilded. Modern masks are made from gesso, are hand painted and have application of gold leaf, gems and feathers.

A photo series by Mark Plessier about the Venetian Carnival was used as inspiration and reference.