Specifying which parts of a mask are inside and outside

The image area inside the mask outline is fully opaque, and the area outside the mask outline is transparent. If you want to create the appearance of a hole in a video layer to reveal a layer underneath, switch the inside and outside areas by inverting the mask. You cannot change the mask state using keyframes; a mask is either inverted or not inverted for the entire duration of a composition.


Default behavior for a drawn mask (left); same mask inverted (right)

To invert a drawn mask:

1. Select the mask you want to invert.
2. In the Timeline window, select the Inverted option next to the mask name.

If you have multiple masks in one layer, you can apply mask modes to create complex transparent shapes or varying levels of transparency. (See Controlling how masks in the same layer interact.)