HP OfficeJet Pro 7740 - Manual (Page 34)

4. Insert the envelope in portrait orientation and with the side to be printed facing down.
Make sure the stack of envelope is aligned with the appropriate paper size lines on the front of the tray.
Also, make sure the stack of envelope does not exceed the stack height marking on the right edge of the
tray.
NOTE: Do not load paper while the printer is printing.
5. Adjust the paper-width guides and the paper-length guide until they touch the edge of the stack of
paper.
6. Check the input tray area inside the printer. If there is paper, remove the paper.
ENWW Load paper 21