If you're reading a chapter about printing and graphics, you may someday be interested in creating screenshots—printable illustrations of the Mac screen.
Screenshots are a staple of articles, tutorials, and books about the Mac (including this one). Mac OS X has a secret built-in feature that lets you make them—and includes some very cool convenience features.
Here's how to capture various regions of the screen.
Press Shift-⌘-3 to create a picture file on your desktop, in PNG format, that depicts the entire screen image. A satisfying camera-shutter sound tells you that you were successful.
The file is called Picture 1.png. Each time you press Shift-⌘-3, you get another file, called Picture 2, Picture 3, and so on. You can open these files into Preview or any other graphics program, in readiness for editing, printing, or exporting in a different format.
It doesn't have to be Shift-⌘-3. You can change this keystroke, or any of these screenshot keystrokes, to anything you like. Open System Preferences→Keyboard & Mouse→Keyboard Shortcuts. Expand the Screen Shots list. Click the keystroke you want to change, and then press the new key combo you prefer.
You can capture just a rectangular region of the screen by pressing Shift-⌘-4. Your cursor turns into a crosshair with two tiny digital readouts—the horizontal and vertical coordinates of your cursor on the screen at this moment. (The numbers are pixels, as measured from the ...