Brother MFC-P2500 User Manual page 36

To print on both sides of the paper from the paper cassette
1.
From the driver, select the required manual duplex print mode.
2.
The printer will print all the even numbered pages first.
3.
Remove the printed even numbered pages from the output tray. Re-insert them
in the paper cassette, with the side to be printed (blank side) face down, and
the top edge toward you. Follow the instructions on the computer screen.
4.
The printer will now automatically print all the odd pages on the reverse side
of the paper.
Fig. 1-19 Paper orientation for the paper cassette
1-27
CHAPTER 1 ABOUT THIS MACHINE