HP Deskjet 6122 Color Inkjet Printer - Manual (Page 60)

4. Push the envelopes forward until they stop.
5. Slide the paper guides firmly against the edges of the envelopes.
6. Replace the Out tray.
printing the envelopes
If your software program includes an envelope-printing feature, follow
the instructions provided with the software program. Otherwise, follow
the instructions below.
1. Open the Printer Properties dialog box, then select the following settings:
tab setting
Setup
Paper Type: Automatic or Plain Paper
Paper Size: Appropriate envelope size
Orientation: Appropriate envelope orientation
Paper Tray: Upper
2. Select any other desired print settings, then click OK .
For a description of available print options, see print settings .