The Set Matte effect replaces the alpha channel (matte) of a layer with a channel from another layer above it for the creation of traveling matte results. The Set Matte effect is intended only to provide compatibility with projects created in earlier versions of After Effects that use the Set Matte effect.

This effect works with 8-bpc and 16-bpc color.

Original (top left), matte layer (bottom left), and result (bottom right)

Although you can use Set Matte for a traveling matte, it’s easier and faster to create traveling mattes by using a track matte. (See About track mattes and traveling mattes.)

Take Matte From Layer

The layer to use as the replacement matte.

Use For Matte

The channel to use for the matte.

Invert Matte

Inverts the transparency values of the matte.

Stretch Matte To Fit

Scales the selected layer to match the size of the current layer. If Stretch Matte To Fit is deselected, the layer designated as the matte is centered in the first layer.

Composite Matte With Original

Composites the new matte with the current layer, rather than replacing it. The resulting matte allows the image to show through only where the current matte and the new matte both have some opacity.

Premultiply Matte Layer

Premultiplies the new matte layer with the current layer.