Solution
This printer automatically mixes the ink at fixed intervals to keep the ink density even.
You can also disable this function by clicking the Custom Settings button on the Maintenance tab and unchecking the Execute ink quality maintenance automatically check box. You should normally check this check box when using the printer.
Note that the ink density may become uneven when this setting is disabled. Therefore when you disable this setting, be sure to execute the following operation about once a week.
The procedure for executing ink quality maintenance manually is as follows:
Ink Quality Maintenance
1. Open the printer driver setup window
2. Click Ink Quality Maintenance on the Maintenance tab
Click OK when a message appears.