Oki C 5400n - Manual (Page 272)

Windows: Postscript Emulation Driver • 270
Printing Custom Page Sizes
NT 4.0
The printer media size for the tray you’re using must be manually set
in the driver to the custom paper size before use (range 3½'' to 8½''
[89 to 216 mm] wide x 5'' to 14'' [127 to 356 mm] long).
1. Make sure the rear exit path is open:
2. Load the custom paper in the tray of your choice.
3. Open the file in your application and select File → Print .
4. In the Print dialog box, select the Postscript emulation printer,
then click Properties .
NOTE
One custom paper size can be defined in the Windows
NT 4.0 Postscript emulation driver.