Containers are a convenient way
            of grouping elements on the timeline. The elements, which can come
            from different layers, can be edited as a unit and individually.
            A matte container is a container with the RGB portion of an image
            on one track and its matte on another. If the matte for a clip exists
            separately from it, you can add the clip and its matte to the timeline
            as a single element by creating a matte container for them. 
         
         For single-frame mattes
            and virtual sources, there are special considerations. If the matte
            consists of a single frame, it is automatically repeated to match
            the duration of the front clip. If both the front and matte clips
            are virtual sources, the matte container is created as a virtual
            source. You can trim, slip or slide it to any extent.
         
         You can create a matte
            container in the following ways:
         
         
            - Using the Axis soft effect quick menu
               or editor.
            
- Using
               the Ctrl hotkey.
            
- By importing the RGBA file directly into
               a matte container. See 
                        Importing RGBA Files.
               (This option does not repeat single-frame mattes to match the front clip.)
            
- Using
               the Container Fx tool. See 
                        Fx Tools. 
            
To create a matte container using the
            quick menu:
         
         
            - Load your fill to the timeline and apply
               a soft Axis to it.
            
- In the Axis quick menu, click Matte.
            
- Select your external matte from the EditDesk.
               NoteYou cannot use a
                     timeline element as your matte selection.
                   
A matte container is
                  created. 
                
To create a matte container using the
            editor:
         
         
            - Load your fill to the timeline and apply
               a soft Axis to it.
            
- Enter the Axis Editor.
            
- Click Load Matte.
            
- Select your external matte from the EditDesk.
               NoteYou cannot use a
                     timeline element as your matte selection.
                   
The matte container is
                  created.
                
To create a matte container using the Ctrl hotkey:
         
         
            - Make sure your fill is on the Primary
               video track of the EditDesk record timeline.
            
- Make sure your matte is on the Secondary
               video track.
            
- Select the element(s) you want to use
               for the fill.
            
- Select the element(s) you want to use
               for the matte.
            
- Ctrl-click
               the Container button.
               The matte container is
                  created on the Primary video track.
                
- Apply a soft Axis to the matte container.
               You now see the result
                  of the external matte with the matte container.
                
To enter a matte container:
         
         
            - Double-click the matte container or click
               E beside the Container button.
               The matte container contains
                  two tracks: your fill on V1 and the external matte you selected
                  on V2. You edit the contents of a matte container the same way as
                  a normal container.
                
To mute a matte from the Axis Editor:
         
         
            - Select the matte container.
            
- Enter the Axis Editor.
            
- Select Off from the Matte box.
               The matte is temporarily
                  removed from the vertical edit. 
                
To mute a matte from the timeline:
         
         
            - Click the Container button.
               The LED turns yellow.
                NoteTo unhide the matte,
                     click the Container LED button so that it turns purple.