Samsung SCX-8128NA-XAA - Manual (Page 43)

Media and tray_ 43
3. Load the paper with the side to be printed on facing down.
4. Squeeze the multi-purpose tray paper width guides and adjust them
to the width of the paper. Do not force too much, otherwise the paper
will bend resulting in a paper jam or skew.
5. When you print a document, set the paper type and size for the
multi-purpose tray (see "Media sizes automatically detected" on
page 44).
For information about setting the paper type and size on the control
panel (see "Tray setting" on page 47).
The settings made from the machine driver override the
settings on the control panel.
To print from an application:
a) Open an application, and start the print menu.
b) Open Printing Preferences (see "Opening printing
preferences" on page 101).
c) Press the Paper tab in Printing Preferences, and select
an appropriate paper type, size, and source.
d) Press OK.
e) Start printing from an application.