Sergei Prokhnevskiy shows how to apply a single mask to multiple layers in After Effects.
The set matte effect can easily tell any number of vector objects that are sitting on your layer list, just by selecting them and choosing “Set as Mask.”
With all of the layers set to use a matte effect, you only have one mask. This is created by using vector shapes which are hidden from Ae’s view in this case.
You can apply a single mask to many layers in After Effects without using any Track Mattes or Blending Modes.
To create a track matte, you need to firstly prepare your media. If it’s going onto video then make sure that the footage has been syncronized and all audio tracks are synced as well so they can be added on top of each other seamlessly without any pauses or jumps in time between them
When adding multiple layers with set mattes there is one issue which will arise depending upon what type of content we’re using for those particular additions: Sergei offers some solutions here too!