Prosthetics are (usually custom-made) artefacts to be attached to the face and/or body of an actor, in order to create an effect on his physical appearance. Injuries and wounds, as well as human mutations and unusual extremities of extraterrestrial beings are most commonly the works of so called „prosthetic artists“, which are regularly found in films. Prosthetic artists work in close collaboration with the make-up artist on set, and are responsible for the design, production and adjustment of their creations. Prosthetics are either bought or rented by a film production.