![background image](https://i.printerdoc.net/HP LaserJet 1320 Printer series/en/HP LaserJet 1320 Printer series_en067.png)
Mac OS 9
1. Do a File-Print, select Layout, and select Print on Both Sides.
2. If the Print on Both Sides check box does not appear, perform the following steps:
a. On the desktop, click Printer queue.
ENWW
Automatic two-sided printing (duplex)
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![background image](https://i.printerdoc.net/HP LaserJet 1320 Printer series/en/HP LaserJet 1320 Printer series_en068.png)
b. On the Menu bar, select Printing-Change Setup.
c. On the Installable Options-Change menu, select Duplex Unit.
d. On the To menu, select Installed.
e. Click OK.