Track Matte

A track matte uses one layer as a stencil that controls where another layer is visible. The matte layer's brightness (luma matte) or transparency (alpha matte) decides which parts of the layer beneath show through and which are hidden. White or opaque areas reveal, black or transparent areas conceal, and grays produce partial transparency. Editors and motion artists use track mattes to reveal footage through text, confine a graphic to a shape, create custom wipes and transitions, or composite an element only inside a defined region. In After Effects and Premiere you assign a layer as a luma or alpha matte for the layer directly under it. Track mattes are a foundational compositing tool because they let you build precise, animatable transparency without permanently altering the source footage.