If you own a Canon printer and are looking at this article, chances are you just got the "Waste ink absorber is full" error, or something similar, and have no idea what it is or what the printer expects you to do. Unfortunately, or fortunately, you are not the only one with this problem and there are ways to solve it. If you call Canon support, they will promptly tell you to bring the printer for servicing, that doesn't help, however, when you have a report or resumé to print by tomorrow.
Firstly, it might be important to note that the waste ink absorber is a little pad that sits under the cartridge's "home" position and collects any loose ink that may be on the cartridge. This prevents smudges, so it's a good thing to have. Many ink jet printers have them, but as far as I know, only Canon PIXMA printers display an error when a certain internal counter suggests that the ink absorber may be full. If you've done a lot of printing, the ink absorber may actually be full and you might need to have it cleaned or replaced to ensure the best printing quality. However, if you haven't printed that much or you have and you just need to print something right this minute, there is a way to reset the counter and stop the error from showing up again. Until the counter reaches a certain unknown point, that is, in which case you'll have to repeat the procedure.
Unfortunately, the instructions for resetting the counter differ from printer to printer and again, as far as I can tell, are not mentioned in the manual. People have been able to figure out how to do it, however, and there are instructions online for many printers. Searching for your printer model and either "ink absorber" or "used ink tank" should provide you with a few links to check out. Almost all of them are pretty easy to follow, albeit contrived and not easily discoverable on your own. Once the counter is reset, you should be able to print again.
If the ink absorber pad in your Canon is indeed full, you might want to replace it. Having it serviced is generally not a good option, since it will likely cost almost as much as the original cost of the printer and is not covered under warranty, since it's considered normal wear and tear and not a defect. Canon will, however, sell you a new ink absorber that shouldn't be too hard to replace. The number to call, in the United States, is 732-521-7230, which is their New Jersey parts center. They are open Monday through Friday, 9:00am to 8:00pm EST and should be able to sell you a replacement. You can also try to clean the ink absorber on your Canon without replacement using tissue to absorb as much ink from the absorber as you can.