In this module, we will take a look at yet another way to make selections in photoshop, masks. Masks can be compared to using masking tape to protect and area of an object or image. The area that is masked is protected. Masking is an even more sophisticated way of making selections than what we have used so far. Moreover, a mask can be saved as a channel and stored in the channels palette. This is a very useful and time saving feature. Any selection, made by any selection tool, can be saved as a mask. As we begin using masks, there are a couple of things that you need to be aware of. First, you can create temporary masks called quick masks, as a matter of fact, all masks are temporary until you save them. If you do not save a quick mask, it will be gone after you save and close your file. Also, any changes you make to your quick mask are permanent. However, if you save a mask as a channel, it will be stored in the channels palette until you delete it. Saved channels can also be exported to other documents. Imagine spending countless hours making a selection using the lasso or magic wand tools, wouldn't it be great to be able to save that selection if you ever needed to use it again. By saving your selection as an alpha channel, you can use it over and over again.
In the quick mask mode, you will be painting on a mask or erasing part of a mask using a brush. This allows you to make extremely complex selections, especially when all of the other selection tools won't work. This is useful when you have textured backgrounds, when your selection includes hair or feathers. You will also be using a tool, the "Extract command" that gives you a quick alternative for separating and extracting objects from a background.