Oki C5550 MFP User Manual page 216

1. In the driver's [Layout] tab, choose [Booklet] from the
[Pages Per Sheet] drop-down list.
PS Booklets_oda.jpg
2. Check that the duplex option is set to [Flip on Short
Edge].
NOTE
If the Booklet choice is not shown, check that the Duplex
option is enabled in the driver.
options" on page
("Setting the driver device
185)
C5550 MFP User's Guide
A guide to printing > 216