> For the complete documentation index, see [llms.txt](https://assimilate.gitbook.io/live-fx-documentation/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://assimilate.gitbook.io/live-fx-documentation/compositing/working-with-mattes.md).

# Working with Mattes

You can use black and white mattes in various ways in Assimilate.

Let's say we want to bring in a Z-Depth Matte, to control the Depth Of Field of our scene.

1. Make sure your [Z-Depth Layer channels are mapped correctly.](/live-fx-documentation/compositing/re-map-exr-channels.md)
2. Create a new layer from the left panel.
3. Fetch or Import your matte.
4. Go to the Fill/Matte Menu.
5. Drop the matte in the "Drop Layer Matte" field<br>
6. Change the layers to NOT use the Alpha channel.\
   This is incorrect:

   This is correct:

Now that the matte is set up, any adjustments that we make to this layer will use the Matte to influence the effect.