I thought Firefox used the default settings for the printer rather than sending specific settings, but that could be different now. Is there any way to save the long edge setting in that Printer Properties dialog so it can't reset to short edge?

That's what I'm trying to find out. I tried changing it to long edge but every time I closed the dialog box it reverted back to short edge.

This seems to be related to a problem we had in Firefox 85 where we mapped long&short edge incorrectly. It was recently fixed in Firefox 86. I'd encourage you to update to the latest version and see if this fixes your problem.

That worked! Thank you so much!

This is really irritating and upsetting my ability to work. I have Firefox 86 but still do not have duplex printing - the second page prints upside down. Do I need to use an alternative browser?

I have Firefox 86 but still do not have duplex printing - the second page prints upside down.

The second page prints upside down on a separate piece of paper?

(A) Duplex Setting

You can switch between short-edge and long-edge binding manually if needed:

(1) In a new tab, type or paste about:config in the address bar and press Enter/Return. Click the button accepting the risk.

(2) In the search box in the page, type or paste duplex and pause while the list is filtered

Firefox should list the print_duplex value for each printer. Printers you have not yet used in the new print experience will have a weird number that is not on this list:

• 0 => print single-sided
• 1 => print double-sided, with long-edge (portrait mode left-right) binding
• 2 => print double-sided, with short-edge (portrait mode top-bottom) binding

To edit a value, double-click the current value to display an editing field. Change it as you wish, then press Enter or click the blue check mark button to save the change.

(B) If the Printer does not comply

You might need to use the "Print using the system dialog" link at the lower right (see attached screenshot).