Oki B401 User Manual page 129

SYMPTOM
Print is darker
than usual.
Pages curl
excessively.
PROBLEM
Darkness setting is too
high.
Printing on wrong side of
paper.
Moisture in paper.
Improper storage.
High humidity.
129 > B401/B411/B431
SOLUTION
Change darkness
setting.
Turn paper over in tray.
(Note arrow on paper
package). Install paper
print side down in tray.
Avoid storing paper in
areas of excessive
temperature and
humidity. Store paper
in protective wrapping.
Recommended
operating humidity: 20-
80%.