Lexmark C77x - Manual (Page 60)

Loading standard trays and optional trays
60
Printing
4 Slide the bottom support toward the front of the tray until it touches the front guide.
5 Flex the sheets back and forth to loosen them, and then fan them.
Do not fold or crease the paper. Straighten the edges of the stack on a level surface.
6 Place the paper against the back left corner of the tray, print side down.
Do not load bent or wrinkled print media.
7 Close the tray.
Make sure the tray is pushed completely into the printer.
Note: Do not exceed the maximum stack height. Overfilling the tray may cause paper jams.