Understanding the concepts that are fundamental to the workflow and tools used for keying will help you work efficiently and effectively, producing the cleanest, most convincing result.

You can create composites by defining transparent regions in a foreground image, based on a specific range of color, to reveal a background image. This keying process is usually performed on footage with a subject in front of a blue or green screen. When you key out a color, you generate a matte: a black and white template indicating which parts of the image are transparent (black), and which are opaque (white). Using techniques, such as softening the edge of mattes, you can refine the results to create realistic composites.