Files going to press are generally printed at 300 dots per inch. As a result, the file size can become very large, depending upon the photos and graphics used in it. By using a layout program and linking these graphics and images (but not saving all of them in the file itself), the working file is a fraction of the file size. When the designer is ready to go to press, s/he will either create a press-ready PDF; or use the "Package" function in InDesign, or the "Collect For Output" function in QuarkXpress or CorelDRAW (which gathers the layout document, plus all fonts and images used therein, and saves them in one folder which can be provided to a commercial printing company for final output).