Canon LASER SHOT LBP3500 User Manual page 63

When outputting A4 size paper or other large-size paper to the sub-output tray, pull
out the auxiliary tray to prevent the paper from hanging out of the sub-output tray.
When outputting A3 size paper or other long-size paper to the sub-output tray, open
the tray extension. When you use the tray extension, gently open it until it stops.
2
IMPORTANT
Be sure to close the sub-output tray before performing automatic 2-sided printing.
•
Do not open the sub-output tray during automatic 2-sided printing.
•
2-20 Output Tray