Lexmark T630 User's Reference Manual page 51

Loading print media in standard and optional trays
5
Place the print media into the tray with the recommended print side face down for single-
sided printing and face up for duplex printing. Do not fill paper above the load line. Overfilling
the tray may cause jams.
6
Squeeze the width guide tab and the side of the guide together. Slide the width guide to the
left until it lightly rests against the edge of the stack.
Load line
51