Lexmark C510 Guide D'installation page 37

Warning:
When you load the tray, do not exceed the load
line on the label in the tray. Overfilling the tray may cause
jams.
Note:
Refer to "Loading envelopes in the standard tray"
in the Media specifications chapter of your User's
Reference for information about loading envelopes.
6
7
8
Load paper
31
Load the stack with the
recommended print side faceup.
Load the stack toward the rear of
the tray as shown.
If you load letterhead paper, place
the header faceup at the rear of
the tray as shown. For two-sided
printing, place the header
facedown at the front of the tray.
If you are loading an optional legal
tray, close the cover.
Re-insert the tray.