Samsung ML-2251NP - Manual (Page 61)

U SING P RINT M ATERIALS
3.10
3 Prepare a stack of paper for loading by flexing or fanning
the paper back and forth. Straighten the edges on a level
surface.
4 Place paper on the centre of the tray with the print side
face up. Pay attention to the paper limit mark on the left
inside wall of the tray. Paper overloading may cause paper
jams.
If you want to print on previously printed paper from the
Multi-Purpose Tray, the printed side should be facing down
with an uncurled edge to the printer. If you experience
problems with paper feed, turn the paper around.
N OTE : Make sure that you have not loaded too much print
material. The print material buckles if you load a stack that is too
deep or push it in too far.