Adobe Photoshop uses masks to isolate and manipulate specific parts of an image. A mask is like a stencil. The cutout portion of the mask can be altered, but the area surrounding the cutout is protected from change. You can create a temporary mask for one-time use, or you can save masks for repeated use.
In this lesson, you’ll learn how to do the following:
Refine a selection using a quick mask.
Save a selection as a channel mask.
View a mask using the Channels palette.
Load a saved mask and apply effects.
Paint in a mask to modify a selection.
Make an intricate selection using the Extract command.
Create and use a gradient ...