Canon MultiPASS F20 Software User's Manual page 54

Cleaning (Head Cleaning)
Removes blockages in the printhead nozzles.
Use if printing is blurred or a particular color is not printing even
though there is enough ink.
Click Cleaning and in the Print Head Cleaning dialog box choose
from one of the following and then click Execute.
When the following dialog box appears, click OK. Do not perform
another operation while the printhead is being cleaned.
In Windows 2000/XP, cleaning begins immediately when you click
Execute.
Please note that if you use Cleaning too often, the ink will be
consumed quickly.
Chapter 3
All Colors: To clean color and black.
Black: To clean black only.
Color: To clean color only.
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