How to Use Track Mattes in After Effects

A workflow taught by Adobe Certified Instructors at Adobe Video World.

A track matte uses one layer to define the visibility of another — letting you reveal video through text, mask footage with a shape, or create elegant transitions. It’s one of the most-used compositing techniques in After Effects, and once it clicks, a world of reveals opens up. This guide explains alpha and luma mattes and how to use them.

What a Track Matte Is

A track matte uses the shape or brightness of one layer to control what’s visible in the layer below it. The matte layer itself usually doesn’t render — instead, it acts like a stencil, cutting the layer beneath into its shape.

The classic example is video showing through text: the text is the matte, and the footage beneath appears only inside the letters. This stencil relationship between two layers is the heart of how track mattes work.

Set Up a Track Matte

To create one, place your matte layer directly above the layer you want to reveal. Then, in the timeline’s Track Matte (TrkMat) column, set the lower layer to use the layer above as its matte, choosing alpha or luma.

After Effects then hides the matte layer and uses it to define the visibility of the layer below. If you don’t see the TrkMat column, enable it via the timeline’s column menu, and the setup takes only a moment.

Alpha Mattes

An alpha matte uses the transparency of the upper layer to define visibility. Wherever the matte layer is opaque, the layer below shows; wherever it’s transparent, the layer below is hidden, making the layer’s shape the reveal area.

This is the matte you use for revealing footage through text or a solid shape — the text’s letterforms are opaque, so the video appears inside them. Alpha mattes are the most common type and the natural choice for shape-based reveals.

Luma Mattes

A luma matte uses the brightness of the upper layer instead of its transparency. Bright areas of the matte reveal the layer below, dark areas hide it, and grays produce partial transparency, giving soft, graduated edges.

Luma mattes are perfect for reveals with soft gradients, like a glow or a textured wipe, where you want feathered rather than hard edges. Choosing between alpha and luma comes down to whether shape or brightness should drive the reveal.

Reveal Video Through Text

The signature track matte effect is footage playing inside text. Put your text layer above your video, set the video to use the text as an alpha matte, and the footage appears only within the letters — a striking, professional title look.

Animate the text or the footage for extra impact, like video drifting inside a bold title. This technique, combined with the styling in our motion graphics guide, produces title cards that look genuinely high-end.

Create Reveals and Transitions

Track mattes drive elegant reveals. Animate a shape matte growing to uncover the layer beneath, or slide a gradient luma matte across to wipe one element into view, building custom transitions you can’t get from presets.

These animated mattes are how motion designers create signature reveals and wipes. Because you control the matte’s shape and movement entirely, the possibilities go far beyond standard transitions, limited only by what you can animate.

Track Mattes vs. Masks

Track mattes and masks both hide parts of a layer, but differently. A mask is drawn directly on a single layer to crop it, while a track matte uses a separate layer’s shape or luma to define another layer’s visibility.

Use a mask when a layer’s own shape is enough, and a track matte when you want one layer — like editable text or moving footage — to drive another’s visibility. They complement each other, and skilled compositors choose based on what’s driving the reveal.

Keep Mattes Organized

Because matte layers hide once linked, it’s easy to lose track of them in a complex project. Label your matte layers clearly and keep them positioned right above the layers they control, so the relationship stays obvious.

After Effects has streamlined matte assignment in recent versions, but clear naming still saves confusion. An organized matte setup means you can revisit and adjust the reveal later without untangling which layer drives which.

Track Matte Best Practices

• Place the matte layer directly above the layer it controls.
• Use an alpha matte for shape-based reveals, luma for brightness.
• Reveal video through text with a text alpha matte.
• Animate the matte for custom reveals and transitions.

Common Track Matte Mistakes

• Placing the matte layer below instead of above.
• Choosing luma when alpha was needed, or vice versa.
• Losing track of hidden matte layers in a busy project.
• Using a track matte when a simple mask would do.

A Real Track Matte Example

Imagine a travel intro where the word ‘EXPLORE’ fills with drone footage of a coastline. You place the bold text above the footage, set the video to use the text as an alpha matte, and the waves and cliffs now move inside the letters. Animating the footage drifting slowly adds life within the type.

To finish, you animate the whole title scaling up gently and add a soft drop shadow behind it for separation from the background. The result is a premium-looking opener built entirely from one text layer acting as a matte over a single video clip — the everyday magic of track mattes.

Animate a Matte for a Reveal Wipe

Track mattes shine when the matte itself moves. Draw a shape on a solid above your layer, set it as an alpha matte, then animate the shape sweeping across or growing outward, and the layer beneath is uncovered in exactly that path. This is how custom logo reveals and shaped wipes are made.

Using a luma matte with a soft gradient instead gives the wipe feathered, gradual edges rather than a hard line. These animated mattes let you design reveals far beyond preset transitions, and because you control the matte’s motion completely, the only real limit is your imagination.

The same reveal is achievable in Premiere using the Track Matte Key to play video inside text, without opening After Effects.

Where track mattes use a layer’s alpha or luma to reveal another, the Set Matte effect in After Effects loads one layer’s channels as a matte without stacking-order tricks.

A key produces a matte, and the Premiere Pro Ultra Key turns that selection into a transparent layer.

A mask that follows movement is the core of tracking and blurring a face in Premiere Pro, just like working with track mattes.

Key Takeaways

• A track matte uses one layer to control another’s visibility.
• Alpha mattes use transparency; luma mattes use brightness.
• Reveal video through text with a text alpha matte.
• Animate mattes for custom reveals and transitions.

Frequently Asked Questions

How do I use a track matte in After Effects?

Place your matte layer directly above the layer you want to reveal, then in the timeline’s Track Matte (TrkMat) column set the lower layer to use the layer above as its matte, choosing alpha or luma.

What’s the difference between an alpha and luma matte?

An alpha matte uses the upper layer’s transparency to define visibility, ideal for shape and text reveals. A luma matte uses brightness, where bright areas reveal and dark areas hide, giving soft graduated edges.

How do I make video show through text?

Put your text layer above your video and set the video to use the text as an alpha matte. The footage then appears only inside the letterforms, creating a high-end title look.

Sources: Adobe’s guide to track mattes and traveling mattes.