Masks (CS3)
Layers Palette - Masks
A Mask is like a hidden invisible layer that is connected to a main layer. It can contain black, white or any shade of grey. Any area of the mask that is white, is completely visible. Any area that is black is transparent. Grey colors become progressively more transperant as they become darker. You can manipulate a mask like any other layer, including painting on, making a gradient on, filling a selection etc.

The create new mask button is the square box with the white circle inside (near the bottom right).

You can tell if a layer has a mask, because it has a small square beside the main thumbnail (in the picture above the top layer has a mask, the bottom does not.)

**When you are working on a layer, you can either select the layer itself, OR the mask. Select the layer by clicking on the thumbnail itself. Select the mask by clicking the small thumbnail to the RIGHT of the main picture. It will highlight.