How is ink used for various purposes other than printing?

Ink may be used for purposes other than printing. Ink is not only used for printing, but also for cleaning the print head to maintain the optimal printing quality.

The machine has the function to automatically clean the ink jet nozzles to prevent clogging. In the cleaning procedure, ink is pumped out from the nozzles. Used ink for nozzle cleaning is limited to a small amount.
 

Does black-and-white printing use color ink?

Black-and-white printing may use ink other than black ink depending on the type of printing paper or the settings of the printer driver. So, color ink is consumed even when printing in black-and-white.