You've probably had this experience: Your printer tells you it's time to change the cartridge, but you dismiss the message and keep printing. Days or weeks later, you're still using the same cartridge and thinking to yourself that rumors of its death were greatly exaggerated.
Or perhaps your printer simply shuts down when it decides you've gone deep enough into its ink well, refusing to operate until you replace the cartridge, though you suspect there's plenty of ink left.
PC World decided to do some real lab testing on this issue; and the results confirm what you may have suspected: Many manufacturer-branded (OEM) and third-party (aftermarket) vendor cartridges leave a startling amount of ink unused when they read empty. In fact, some inkjet printers force users to replace black ink cartridges when the cartridge is nearly half full, PC World has found.
We tested using multifunction printers from four major manufacturers: Canon, Epson, Hewlett-Packard, and Kodak. PC World Test Center results show that models from Canon, Epson, and Kodak reported ink cartridges as being empty when in some cases the tanks had 40 percent of their black ink remaining.
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. After posting low-ink warnings, those printers wouldn't let us resume printing until we inserted a new cartridge.
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.
When using ink their own manufacturer's cartridges, the printers displayed several low-ink warning messages before finally shutting down due to low ink. Our HP printer, the Photosmart C5280, was the only one that continued to print even after displaying several low-ink messages, and those messages appeared only when we used an HP print cartridge. When we paired the C5280 with an aftermarket cartridge from LD Products, the printer provided no low-ink warning at all.
It's important to note that our results show the performance of a clutch of single printers, each paired with just one 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 kind of snapshot of the way each particular unit deals with "remaining ink."
Why So Much Leftover Ink?
There are valid reasons for not draining an ink cartridge completely, printing experts say. "Many inks, if they run dry, can cause significant damage to the printer," says Brian Hilton, a senior staff engineer at the Rochester Institute of Technology who holds 29 inkjet patents. "You always want to leave a buffer in the tank so that the printer never runs dry. There should always be a factor of safety included."
Other observers point out that the quantity of leftover ink is often only a few milliliters. "Printers have generally become more efficient over the years," says Andy Lippman, a printing analyst with Lyra Research. "In the past, you might have seen 40 milliliters of ink in the black cartridge. Today you're going to get the same amount of pages out of 7 or 8 milliliters."
Other people, however--both journalists and independent researchers--have reported very different experiences with ink cartridges. Judging from these findings, printer owners are probably throwing away a lot of usable ink. And that's a problem, when you consider how expensive the precious fluid is. An average black-ink cartridge contains 8 milliliters of ink and costs about $US10 which translates into a cost of $1.25 per milliliter (or more horrifyingly, $1250 per liter).