Brother MFC-L6750DW Online User's Manual page 553

Examples of poor print quality
Curled or wavy
Wrinkles or creases
Poor fixing
ABCDEFG
EFGHIJKLMN
Envelope creases
Related Information
• Troubleshooting
• Test Print
• Clean the Drum Unit
Recommendation
• If the problem only occurs during automatic 2-sided
printing, check for torn paper in the 2-sided tray. Verify
the 2-sided tray is inserted completely and the back
cover is closed completely.
• Check the paper type and quality. High temperatures
and high humidity will cause paper to curl.
• If you do not use the machine often, the paper may
have been in the paper tray too long. Turn over the
stack of paper in the paper tray. Also, fan the paper
stack, and then rotate the paper 180° in the paper
tray.
• Open the back cover (face up output tray) to let the
printed paper exit onto the face up output tray.
• Choose Reduce Paper Curl mode in the printer driver
when you do not use our recommended print media.
• Make sure paper is loaded correctly.
• Check the paper type and quality.
• Turn over the stack of paper in the tray or rotate the
paper 180° in the input tray.
• Make sure the media type setting in the driver
matches the type of paper you are using.
• Choose Improve Toner Fixing mode in the printer
driver.
If this selection does not provide enough
improvement, change the printer driver setting in
Media Type to a thick setting. If you are printing an
envelope, choose Env. Thick in the media type
setting.
• Make sure envelopes are printed with the back cover
(face up output tray) opened.
• Make sure envelopes are fed only from the MP tray.
546