After you've perfected your perspective drawing, the next step in the matte painting process is to layer in tone: the master tool in the matte artist's arsenal for establishing a fully formed structure. David Mattingly, a matte artist for many groundbreaking motion pictures, takes a black-and-white drawing and shows how to use the five elements of light—dark sides, light sides, cores, cast shadows, and final darks— to paint the surfaces and create a realistically shaded environment in Adobe Photoshop.