Using Masks with Keys

Use a mask operator to mask out unwanted portions of a key (for example, a rig in a shot or "dirt" left from a key).

To clean up the matte, a mask operator can be applied above the Keyer operator in the stack.

Note: Since the mask and the keyer both affect the layer's alpha channel, the stacking order (of the mask and keyer) does not matter.

To use one or more masks, select Intersect and enable Invert in the Global Apply Mode settings.

The masks remove the area inside the mask shape and keep the area outside the mask shape, like a "garbage mask."

You can also apply a mask operator to remove a rig or other problem area prior to pulling the key (applying the Keyer operator).

In the following example, Invert is disabled and the mask removes the area outside the mask shape and keeps the area inside the mask shape. This is a "holdout mask."