Turn on Default Duplex Printing on Mac

When I bought my Brother duplex capable printer the first thing I wanted to do was make sure my printer was using duplex by default.  However after the initial setup I found that to get duplexing to work I would have to press the "two sided" box in the print settings dialog every time I wanted to print.  To this end I finally found a solution that removed the need to click the button, it is as follows.

One note before we begin, for this to work your printer must support duplexing and must be setup on your Mac.

1. First you will need to get to the CUPS web configuration page.  In a browser enter the address 127.0.0.1:631 into the address bar. The CUPS page should greet you. Next click the "Printers" tab in the upper right corner.

2. A list of all the printers and scanners that are currently installed on your Mac will appear on the screen.  Under the queue name header choose the printer that you want to change.  In my case I selected my Brother HL 4040CDN from the list.

3. A detailed list of the printers description, location, and defaults will be shown. Click the drop down box "Administration" and select 'Set Default Options' your browser will automatically take you to the default options page.

4. On the set default options page select the duplex drop down box and change the selection from 'None' to 'DuplexNoTumble'. If you were to select DuplexTumble the printer will invert the backside of duplexed sheets such that you will need to rotate the page to read it.  While DuplexNoTumble will not invert the backside of duplexed sheets.

6. Click the 'Set Default Options' button at the bottom of the page. An authentication box will popup asking for your account name and password.  Enter both and press log in.

7. If everything worked you will be greeted by a confirmation page and duplex printing will be on by default in the printer options page.