Oki C 9400 - Manual (Page 55)

Check setting to Off.
8. Click Print.
Envelopes
Caution! The ink in preprinted return addresses must be able to withstand 392°F
(200°C) for 0.1-second.
Envelope Recommendations
Important!
Use envelopes with a smooth, even surface that are designed for laser printers: no
metal clasps, snaps, windows, or self-adhesive flaps.
Folds should be well scored and sharply creased.
Envelopes containing air can wrinkle as they pass through the printer.
Be sure to test sample envelopes first before buying in quantity.
Yes!
No!
54