Brother HL-1230 EN - Manual (Page 21)

CHAPTER 1 ABOUT THIS PRINTER
1-12
2.
Pull the paper cassette completely
out of the printer.
3.
Adjust the paper guides at the right
and rear of the paper cassette to
match the paper size you want to load.
Make sure that the tips of the paper
guides fit into the slots correctly.
4.
Load paper into the paper cassette. Make sure the
paper is flat in the cassette at all four corners.