文档介绍：Chapter 10: Learning All About Layers
FIGURE
The clipping mask used the leaf as a template to cut out the jack-o’-lantern image for
a fun fall effect.
On the Web
Check out the final product by downloading Figure 10-31 from the website and looking at the layers.
Creating a clipping mask changed the way the layers look in the Layers panel, but not by
placing a mask thumbnail in the selected layer. Instead, the layer containing the jack-o’-lan-
tern image has an arrow pointing down to indicate that this layer is being affected by the
layer underneath.
You can release the clipping mask by right-clicking the top layer again and choosing Release
Clipping Mask from the pop-up menu.
Editing masks
After a mask thumbnail has been placed in your Layers panel, you can edit it using the image,
the channels, or the Masks panel. This allows you to make changes to which areas of your
image are being affected.
Making changes to a mask by painting on the image
To edit a mask using an image, you must have the mask selected in the layer. Make sure the 10
mask thumbnail has a white highlight around it, rather than the image thumbnail, shown in
Figure . This is sometimes hard to see, so click back and forth a couple of times to see
the difference.
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Part III: Working with Selections, Layers, and Channels
After you have selected the mask, you can use the Brush and Eraser tools to add to or sub-
tract from the masked area. Using the Brush tool adds to the mask and using the Eraser tool
subtracts from it. Use these tools directly on your image. The only difference you see is a
change in the mask’s effects. Depending on what those changes are, this might not be the
ideal way to edit your mask, because it is hard to be precise if the effects of the mask aren’t
obvious.
FIGURE
The white outline showing that the mask is selected means we are making changes to the
mask with the brush, rather than the imag