Brother MFC-J4510DW Basic User's Manual page 42

Chapter 2
a
Open the manual feed slot cover located
at the back of the machine.
34
b
Slide the manual feed slot paper guides
to fit the paper width that you are going
to use.
NOTE
The paper mark (1) in portrait orientation
is on the right side of the manual feed slot,
and the mark (2) in landscape orientation
is on the left side of it.
When you slide the paper guides, confirm
that they are in these positions.
1
2