Canon S450 User Manual page 260

Note • The automatic print head alignment feature may not work properly in the
following circumstances.
– When ink runs out.
– The nozzles of the print heads are clogged.
– The printer is exposed to strong light.
If automatic alignment does not work properly, execute manual print head
alignment.
• To turn off the printer after automatic head alignment, always press the
POWER button to turn off the printer. If you do not turn off the printer
correctly with the POWER button, the print head alignment settings
are not saved.
Aligning the print heads manually
Printer Maintenance
Using the Macintosh Printer Driver 260