Oki C5800 - Manual (Page 29)

Printer settings in Mac> 29
4. Click Preferences.
5. Change Page Setup Preferences or Print Preferences as
required.
These new settings will be saved as the printer driver
defaults.
P AGE S ETUP O PTIONS - G ENERAL
Paper
Choose the paper size that matches your document and the
paper loaded in the printer. The paper margin is 1/6 inch (4.2
mm) at all edges.
Orientation
Selects either portrait (tall) or landscape (wide).
If using landscape, you can flip the orientation 180 degrees.