HP Color LaserJet Enterprise flow M880 Multifunction Printer series - Manual (Page 58)

4. Select the Print on both sides check box. Click
the OK button to print the first side of the job.
5. Retrieve the printed stack from the output bin,
and then place it with the printed-side facing up
in Tray 1.
6. If prompted, touch the appropriate control panel
button to continue.
48 Chapter 4 Print ENWW