Simply put, the master painter is the one in charge of painting for a show. Depending on what the set calls for, the painter can have a variety of responsibilities (including making certain props or texturing building elements). A painter does not have to be a classically trained artist. all that is called for is a good grasp of color, perspective, and a familiarity with using drawing tools. The painter, along with the set designer, is responsible for translating the director’s vision into a finished set. He/she will collaborate closely with the set designer and tech director (probably more so than the lighting designer and costumer, although he/she will definitely be working with them, too). The set designer will be directing the painter, but the master painter often has the freedom to choose many of the design elements.
The painter orders paint, makes and adheres to a painting budget, is responsible for all the painting materials, and directing all assistant painters that are given to him/her. Usually, he/she will help build the materials that need to be painted (the T.D. will be in charge of that), will prep surfaces, paint and possibly seal them, and mix paint colors. It is a very fun job, although it can be a large one.