Editing > Working With Containers, Matte Containers and Multi-channel Clips > About Matte Containers >

# Adding a Matte to a Matte Container

There are two ways to add a matte to a matte container.

- By entering the matte container and adding the matte to a video track.
- Adding a clip from the library to the timeline without entering the matte container directly.

The matte clip must have the same resolution as the front clip in a matte container.

To enter a matte container and add a matte to it:

1. Display the timeline and the library.
2. On the timeline, double-click the matte container to enter it.
3. Click V+ to add a new track.
4. Drag and drop a clip from the library to the track on the timeline.
5. (Optional) Set the matte as the secondary.

To add a matte to a matte container without entering it:

1. Display the timeline and the library.
2. Select the matte you want to add to the container from the library.
3. Press C trl, drag and drop a matte onto the matte container segment on the timeline to insert the matte at the first frame of the first shot inside the matte container.
4. (Optional) You can drag and drop a matte onto the matte container while holding Ctrl+Alt to insert the matte at the first frame of the In point of your timeline segment rather than the first frame of the source clip. This is useful when working with scene detected footage requiring mattes.

NoteThe Ctrl+Alt option is exclusive to Lustre 2012 Extension 1.

You can drag and drop multiple mattes into a matte container. The first matte you add is the secondary track. You can apply any matte in your container to a separate secondary colour grading layer in the Colour | Secondaries menu. See Selecting a Matte to Grade Secondary Layers.

To add a matte to a stereoscopic matte container, you must drop mattes one at a time to add them to the matte container. You cannot select both a left and right matte at the same time and drop them on a clip to create a stereo matte container.

To add a matte to a stereoscopic matte container:

1. Display the timeline and the library.
2. Hold down Ctrl or Ctrl+Alt and drag and drop a matte onto the matte container segment that corresponds to the stereo eye.
3. Hold down Ctrl or Ctrl+Alt and drag and drop a second matte onto the matte container segment that corresponds to the other stereo eye.

NoteThe Ctrl+Alt option is exclusive to Lustre 2012 Extension 1.