Applying mattes

A matte is a transparent shape that defines the visible area of a separate image. Any part of the image that is within the matte's area is visible; any part that is outside the matte is invisible. A matte that is currently applied to an image object is called an active matte. You can use the Properties palette to apply a matte to an imported image object, cropping the image object to the shape of the matte.

To crop an image object using a matte:

1. Select the image object.
2. Choose Window > Properties.
3. Select Active Matte from the Alpha Channel menu to use a shape to mask the image.

You can also add an active matte using the Matte option in the Library palette by dragging a shape from the Library palette, or by dragging an EPS file from a folder onto the Active Matte display in the Properties palette. The active matte's shape is scaled to the size of the image.


Image object, matte, and matte applied to the image object

Note: If the image has a native alpha channel, the alpha channel and the active matte are combined to create a matte.