Matte refinement overview

Keying is rarely a one-step process. Although adding a keying filter is the first step, there is usually additional work that must be done to create a good key that retains detail around the edge of your subject. You can use the mask tools and alpha channel filters to turn a decent key into a great one:

Important: When using masks with keying, apply any masks after applying the keyer. Additionally, be sure to apply the masks to the same image layer as the keying filter itself.