Today I had a large batch of papers to print and decided that duplex would save a lot on paper and heft, however the driver I had set up for the office networked printer did not support duplexing. I went down a bit of a rabbit hole trying to get everything working, so I'm going to lay out the final process below.
- Determine the IP address of the printer. This can be done by holding down the green "ok" button for several seconds causing it to print the status page.
- Install hplip through your package manager or just "sudo apt-get install hplip"
- Run hp-setup from bash. Choose Network/Ethernet/Wireless and under Show Advanced Options check the Manual Discovery box and type the IP address in the box next to it.
- The next screen should show one entry for your printer, if it does not then either the IP is incorrect or other network issues are present. Assuming it's there, simply click next.
- It will download the HP driver for it (the one that doesn't duplex, strangely) and will have you provide a description, location, etc.
- After the wizard closes, open the System shortcut through unity. From here open up Printing.
- Your newly added printer will be in the list, right click and go to Properties.
- In the window this opens, there should be a line for "Make and Model", click the button next to it that says "Change..."
- At this point it will search for drivers, go ahead and cancel this and select "Provide a PPD file".
- Now is a good time to grab the file for the OpenPrinting.org. Just look for "directly download PPD" and make sure the file name is "Generic-PCL_5e_Printer-hpijs-pcl5e.ppd". Feed this file to the previously opened window.
- With that driver chosen, under "Printer Options" in the printer properties window you can now set an option for Double Sided Printing. Choose "Long edge (standard)".
- Print away, it should finally work. I did end up restarting CUPS a few times (using sudo stop cups and sudo start cups at the terminal).
Best of luck with this demon machine, leave additional confusion in the comments.