HP Color LaserJet 2550 Printer series - Manual (Page 53)

3. Slide the side-width guides in tray 1 outward until they are slightly wider than the
envelopes.
4. Place the stack of envelopes into the tray with the side to be printed on facing up and
with the short edge leading into the printer. The stamp end must enter the printer first.
Note If the envelope has a flap on a short edge, this edge must enter the printer first.
5. Slide the side-width guides inward until they lightly touch the stack without bending it.
The stack should be centered between the guides and must be under the tabs on the
guides.
6. Select the envelope you are using as the Size (Windows) or the Paper Source
(Macintosh) in the Print dialog box or the printer driver.
Printing on labels
Follow these guidelines for using labels. See Print-media specifications for more details.
ENWW Printing on special media 43