AfterEffects
Masks, transparency, and keying
Working with masks and mattes
View mask paths
Select masks, segments, and vertices
Change a mask path numerically
Lock or unlock masks
Copy, cut, save, reuse, and delete masks
Control mask path color
Mask modes
Adjust the edges of a mask
Adjust mask feather
About track mattes and traveling mattes
Convert a layer into a track matte
Preserve underlying transparency during compositing
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