Preserving underlying transparency during compositing

The Preserve Underlying Transparency option specifies that the opaque areas of a layer display only when positioned over opaque areas in underlying layers. With this option, you can make a layer display only when it is positioned over the layer below it. It's useful for creating effects such as glints or light reflecting off a polished surface.

To preserve underlying transparency:

Select the T option in the Layer Switches column for the appropriate layer.


A matte layer before applying Preserve Transparency (left) and after (right).