Printing on both sides of the paper (duplexing)
How to active the duplexer to print on both sides of the paper automatically.
Use the instructions in these steps to make sure that the duplex printing accessory. Do do that, you need to change the print setting.
First, On the Apple menu, click the System Preferences () button; Next, Click Print & Fax.
After that, Select the name of your printer in the Printers list in the left panel.
Click the Open Option button.
Click Printer Setup, and then click the Driver tab.
Highlight the Two-sided Printing Accessory (Duplexer).
After all, you are allow to print on both sides of the paper automatically.