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Move or change the transparent area with Track Matte Key

The Track Matte Key reveals one clip (background clip) through another (superimposed clip), using a third file as a matte that creates transparent areas in the superimposed clip. This effect requires two clips and a matte, each placed on its own track. White areas in the matte are opaque in the superimposed clip, preventing underlying clips from showing through. Black areas in the matte are transparent, and gray areas are partially transparent.

A matte containing motion is called a traveling matte or moving matte. This matte consists of either motion footage, such as a green‑screen silhouette, or a still image matte that has been animated. You can animate a still by applying the Motion effect to the matte. If you animate a still image, consider making the matte frame size larger than the project frame size so that the edges of the matte don’t come into view when you animate the matte.

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Because the Track Matte Key can be applied to a video clip, the matte can change over time.

You can create mattes in various ways:

  • Use the Title panel to create text or shapes (grayscale only), save the title, and then import the file as your matte.

  • Apply the Chroma, RGB Difference, Difference Matte, Blue Screen, or Non Red Key to any clip and then select the Mask Only option.

  • Use Adobe Illustrator or Adobe Photoshop to create a grayscale image and import it into Adobe Premiere Pro.

  1. Add the background clip to a track in a Timeline panel.
  2. Add the clip you want to superimpose to any track higher than the track containing the background clip. This is the clip revealed by the track matte.
  3. Add the track matte clip to a third track above the tracks with the background and superimposed clips.
    If you need to add a new track to the sequence, drag the track matte clip to the empty area above the highest video track in a Timeline panel. A new track is automatically created.
  4. In the Effects panel, click the triangle to expand the Video Effects bin and then click the triangle to expand the Keying bin.
  5. Drag the Track Matte Key to the superimposed clip.
  6. In the Effect Controls panel, click the triangle next to the Track Matte Key name to expand its settings.
  7. Click the Matte setting pop‑up menu with the down‑pointing triangle and choose the video track containing the track matte clip.
  8. (Optional) If you’re animating the Track Matte Key over time, make sure that the current‑time indicator is in the position you want. Click the Toggle Animation icons of the settings you want to adjust.
  9. Click the Composite Using pop‑up menu and choose one of the following:
    Matte Alpha
    Composites using the track matte clip’s alpha channel values.

    Matte Luma
    Composites using the track matte clip’s luminance values.

  10. (Optional) Select the Reverse option to invert the values of the track matte clip.
    To retain the original colors in the superimposed clip, use a grayscale image for the matte. Any color in the matte removes the same level of color from the superimposed clip.
  11. (Optional) If you’re animating the Track Matte, move the current‑time indicator either in the Effect Controls panel or Timeline panel and change the Track Matte Key settings.

    A new keyframe appears in the Effect Controls timeline when you change the settings. You can also adjust the interpolation between keyframes by editing the keyframe graph. Repeat this step as needed.