The page counter doesn't mean that it counts every pages that you are printing but it counts through the ink that has been spit out by your cartridges. Everytime your cartridge spit a dot of ink, it makes a count on it.
The counter just estimates the amount that will become waste that will be sent out through the waste pad inside your printer everytime you do a task(printing or cleaning, nozzle check...). So if your printer had a default counter of approximately 25000 pages, you will be prompted "waste ink absorber is full" if you will reach that page range. That's how your waste ink pad protected upon getting leaked or spilled.
To solved the problem of waste ink absorber is full, you have to reset the counter of your printer back to zero (0).
If you have canon Pixma iP series such as iP1200, 1300, 1880 1980 etc.. you can read my post on how to reset canon pixma iP series? here.
WARNING: Make sure to change the waste ink pad inside your printer after resetting your printer page counter back to zero.
If you don't know how to change the waste ink pad inside your printer, please refer to your nearest expert printer technician to do it for you.
