Samsung ML-4512ND-XAA - Manual (Page 34)

Media and tray
34 2. Menu overview and basic setup
 
8
Loading paper in the tray/ optional tray
1 Pull out the paper tray (see "Tray overview" on page 33).
2 Flex or fan the edge of the paper stack to separate the pages
before loading papers.
3 Squeeze and the paper width guide and paper length lever to
locate them in the correct paper size slot marked at the
bottom of the tray to adjust to the size.
4 Place paper with the side you want to print on facing down.
5 Slide the paper length guide until it lightly touches the end of
the paper stack.