HP LaserJet 8000 Multifunction Printer series - Manual (Page 268)

Appendix A Specifications 268
Paper Specifications
If you do not have an optional envelope feeder, print envelopes from Tray 1,
see page
111 . To print envelopes with the optional envelope feeder, see
page 107 . If envelopes wrinkle, try opening the left output bin.