Lexmark All in One Printer - Manual (Page 50)

50 Loading Print Materials
Loading the
multipurpose feeder
Proper loading helps prevent paper jams and ensure trouble-free
printing.
Do not remove any paper tray while a job is printing from the multi-
purpose feeder or
Busy is displayed on the operator panel. Doing so
may cause a paper jam.
Never add print materials to the multipurpose feeder while the
printer is printing from the multipurpose feeder. Doing so may cause
a paper jam.
Before loading paper, you need to know the recommended print
side of the paper you are using. This information is usually indicated
on the paper package.