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). The Mac has a secret built-in feature that lets you make them—and includes some very cool conveniences. 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. Each time you press Shift-⌘-3, you get another file on your desktop.
These files are named after the current time and date. They’re called “Screen shot 2016-01-18 at 5.18.13 PM,” “Screen shot 2016-01-18 at 5.18.32 PM,” 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 any of these screenshot keystrokes to anything you like. Open System Preferences→Keyboard→Keyboard Shortcuts→Screen Shots. Click the keystroke you want to change, press Return to highlight the current keyboard combo, and then press the new keystroke you prefer.
You can capture just a rectangular region of the screen by pressing Shift-⌘-4. Your cursor turns into a crosshairs with two tiny digital readouts—the horizontal and vertical ...