By default, the printer driver transfers binary information to PostScript printers; however, you can choose to transfer image data using JPEG or ASCII85 encoding. These options are not available to non-PostScript printers such as many inkjet models.

ASCII85 is a text encoding for binary data that is more compact than ASCII encoding.

JPEG-encoded files are smaller than binary files, and therefore require less time to print; however, using JPEG encoding decreases the image quality. Only PostScript Level 2 (or higher) printers support JPEG encoding; sending a JPEG-encoded file to a PostScript Level 1 output device may result in PostScript language errors.

Some print spooler programs, computer networks, and third-party printer drivers don't support files that are binary or JPEG-encoded, and some PostScript output devices accept binary and JPEG-encoded image data only through their AppleTalk and Ethernet ports, not their parallel or serial ports. In these situations, you can select the ASCII85 encoding method. However, ASCII85 files contain about twice as many characters and require about twice as much time to transfer as binary files.

To change the encoding method:

1. Choose File > Print with Preview.
2. Select Show More Options, and choose Output from the pop-up menu.
3. Select an option from the Encoding menu.