Canon IR1600 Reference Manual page 106

6
Set the paper size detecting lever, located on the left side of the paper drawer, to match
the size of the paper being loaded.
IMPORTANT
Be sure to set the paper size detecting lever correctly. If the lever is set to the wrong position, paper jams or dirty prints
may occur, or the inside of the machine may get dirty.
5
7
Stick the appropriate paper size label on the paper size plate.
Remove the protecting plastic sheet and stick the label of the paper size you are loading.
5-8 Loading Paper
A4