Apple Personal LaserWriter300 - Manual (Page 40)

The printer prints on only part of the paper
Make sure you have selected the appropriate paper size in the
Page Setup dialog box.
Check the adjustment of the sliding backstop in the paper
cassette to make sure it is correct for your paper size. See
“Loading the Paper Cassette” in Chapter 2.
Paper is jammed
To avoid paper jams, make sure the paper cassette is properly
loaded with one of the recommended paper types. (See “Paper
Feeds Improperly,” next.) If you are using manual feed, be sure to
wait for the prompt before inserting a new sheet.
Paper jams are sometimes caused by moving or jarring the printer.
32 Chapter 4: Tips and Troubleshooting