Yes, that should work, but that's more trouble than just duping the matte and applying a track matte to each layer.  I'm looking for a way to make things easier, not harder.

The simplest idea I can think of is Precomping all the layers I want to mask, put the matte at the top, and use Stencil Alpha, etc.

That way, any layers under the precomp are exempt from the "master" matte.

Or, is there an even simpler way?

On Sep 14, 2012, at 10:54 AM, Darby Edelen wrote:

To clarify: the matte and footage layers each get their own precomp.

On Sep 14, 2012 5:52 PM, "Darby Edelen" <dedelen@gmail.com> wrote:

Set Matte may work if you precomp both the matte and footage layers (leave all attributes) and set the collapse transformations layer switch on the precomps.