We performed the tests using inkjet multifunction printers from four major
manufacturers: Canon, Epson, Hewlett-Packard, and Kodak. Our results show that when these models reported their black ink cartridges as being empty, the quantity of unused ink ranged from about 8 percent in an Epson-brand cartridge to a whopping 45 percent in an aftermarket cartridge for a Canon printer. Our test printers typically left more unused ink-in some cases significantly more-when using third-party or aftermarket print cartridges than when using the printer manufacturer's own cartridges.

It's important to note that our results show the performance of a small set of printers, each paired with just one brand of cartridge. Since OEMs and their aftermarket competitors sell dozens of ink cartridges for a wide variety of printer models, you should consider our results as a snap¬shot of the way each particular unit deals with remaining ink.