# Matte Key

A Matte Key control is available for some video inputs. When enabled it uses a separate image or video source as an alpha mask: areas where the matte is dark become transparent, and bright areas remain opaque.

Type

Selects the matte source.

-   **None**: Matte Key is disabled.
    
-   **Video**: Use another video source in the project as the matte.
    
-   **Image**: Use an image file as the matte.
    

Source

When **Type** is **Video**, selects which video source to use as the matte.

Image File

When **Type** is **Image**, opens a dialog to select the matte image. Supported formats: .png, .jpg, .jpeg.