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. Check out our video that accompanies this story.

Overview
We tested using multifunction printers from four major manufacturers: Canon, Epson, Hewlett-Packard, and Kodak. (For the top-rated models, see our chart of top-rated multifunction printers.) 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 $10 which translates into a cost of $1.25 per milliliter (or more horrifyingly, $1250 per liter).

Liquid Gold?
If you bought a gallon of the stuff over the life of your printer, you'd have paid about $4731 for a liquid that one aftermarket vendor told us was "cheap" to make. For some perspective, gasoline costs about $3 per gallon (at the moment), while a gallon of Beluga caviar (imagined as a liquid) costs about $18,000--surprisingly, only about four times as expensive as good old printer ink.

"I personally think that consumers are getting ripped off," says Steve Pociask, president of the American Consumer Institute, a nonprofit educational and research institute in Washington, D.C. Pociask recently coauthored a 50-page study on the ink jet printer and cartridge market. "In some cases, we found that [the price of] the printer could be 1/8 of the total cost of printing," says Pociask. "Over the life of the printer--and by that I mean three years--you can easily spend $800 for the printer and ink."

How We Tested
We researched both online and brick-and-mortar tech outlets to find printers that are being used now by high numbers of consumers. We didn't test color inks because that would have introduced too many variables that might skew the results. For instance, some printers use separate cartridges for each ink, while others use single, tricolor cartridges. A standardized test might not drain the colors evenly, which might give one printer an unfair advantage.

Tony Leung, Senior Data Analyst in the PC World Test Center, weighed each black ink cartridge (to an accuracy of 0.001 gram) to determine the cartridge's initial weight. We then printed pages until the printer, in response to the low level of ink in the cartridge, prevented us from continuing.

When each printer stopped printing, we removed and weighed its black ink cartridge to determine the cartridge's out-of-ink weight. Then we removed all of the remaining ink from the cartridge (including the small sponges found in some cartridges), put the cartridge on the scale again, and measured it's true-empty weight.

This method allowed us to identify the weight of the ink when the cartridge was full, when the printer announced that it was empty, and when it truly was empty.

Using this method, here's what we found...

Canon
We tested Canon's Pixma MP610 multifunction printer with black ink cartridges from Canon and from G&G, an aftermarket brand owned by Ninestar Image. The differences in performance between the OEM ink and the aftermarket ink were striking. With the Canon cartridge installed, the printer stopped printing when 24 percent of the ink remained in the tank. Specifically, the full tank of ink weighed 27.333 grams, and the unused ink in the tank at nominal empty weighed 6.459 grams.

Canon didn't dispute our results, but the company pointed out that its printers do allow users to print after the initial low-ink warning. "There are typically a series of warnings before the ink is out, alerting users to ink status," spokesperson Kevin McCarthy wrote in an e-mail message. (We calculated the remaining ink weight at the point when the printer actually shut down, which was after the preliminary warnings appeared.)

When equipped with the aftermarket G&G cartridge, the Canon printer shut down with nearly 45 percent of the ink left. The full tank of ink weighed 27.320 grams, and its remaining ink weighed 12.277 grams.
G&G responded by running its own tests with a different Canon printer, the Pixma iX4000. (The vendor says the model that the PC World Test Center used wasn't available in its workshop at the time of testing.)

G&G told us that it tested three of its color cartridges--magenta, blue, and yellow--and found that the amount of residual ink ranged from 5.5 percent (for yellow) to 17 percent (for magenta). (Again, PC World limited its testing to black ink cartridges only.) Canon declined to comment on our test findings with the G&G print cartridge.

Epson
With an Epson black-ink cartridge installed, the Epson RX680 printer shut down with just over 8 percent of its ink remaining. The weight of the ink in the full cartridge was 11.700 grams; the weight of the residual ink at printer shutdown was 0.969 gram. In an e-mail response to PC World, an Epson spokesperson wrote: "Eight percent remaining ink measured in your testing is a normal amount. This reserve assures print quality and printer reliability."

But the story was quite different when we printed pages on the RX680 using an aftermarket cartridge from LD Products. This time the printer shut down with a whopping 41 percent of the ink still in the tank. The full quantity of ink weighed 12.293 grams; the unused ink weighed 5.0005 grams.

Why the huge gap between OEM and aftermarket? "Epson cartridges have an ink-level sensor to more accurately report ink levels, and to reduce the amount of ink in the safety reserve," the company spokesperson wrote. Third-party products don't have these sensors, according to Epson, and the printer manufacturer "cannot guarantee the performance, quality or longevity of these cartridges."

LD Products has a different theory. "The ink itself is cheap, so we refill to more than the original level," says Ben Chafetz, vice president of marketing for LD Products. The Epson printer bases its low-ink message on the printing capacity of the OEM cartridge, but since the LD cartridge contains considerably more ink than the OEM version, it is bound to have more ink remaining when the printer shuts down, according to Chafetz. In other words, if Epson supplies enough ink in its cartridge for 120 pages plus a margin of error, say, while LD adds enough ink to print 200 pages, and if the Epson printer shuts off at 120 pages anyway, the percentage of leftover ink in the LD cartridge will be considerably higher than in the Epson cartridge.

Chafetz points out that regardless of the percentage of unused (and unusable) ink in the nominally empty cartridges, the page yields of the LD Products cartridges and the high-capacity Epson cartridges should be the same. (Note: PC World didn't test page yields in this study.)

Hewlett-Packard
Testing the HP printer was difficult because HP takes an unusual approach toward diminishing ink supplies in its cartridges: The HP Photosmart C5280 multifunction printer we tested didn't shut down as ink levels approached exhaustion. With an OEM cartridge installed, the printer displayed warning messages as the ink level dropped, but it never forced us to replace the cartridge.

As a result, we continued printing until the pages began showing telltale signs of low ink, such as banded text. The HP printer will continue to print until the cartridge is completely dry--but since the print heads are part of the cartridge in HP's design, running out of ink does not damage other parts of the printer.

When using an aftermarket cartridge from LD Products, the C5280 failed to post any low-ink warnings--either on our test computer or on the printer console. Does that mean HP's warning system works only with house-brand cartridges? Not necessarily, but HP suggests that you are better off with its OEM cartridges. "Most aftermarket cartridges do not signal 'low-on-ink' alerts, giving customers no advance warning that ink is running low," wrote HP spokesperson Katie Neal in an e-mail message.

LD Products' Chafetz disagrees. He says that LD's Photosmart C5280-compatible products are actually refurbished and refilled HP cartridges. One possible explanation for the lack of a low-ink warning is that the printer wasn't reading the refurbished cartridge's chip code correctly, he says.

Chafetz says that the results from PC World's tests mark the first time that LD Products' technicians have heard of their cartridges' not posting a low-ink warning.

Kodak
The Kodak EasyShare 5300 was the only printer that lasted longer with an aftermarket cartridge than it did with the manufacturer's cartridge. Equipped with a Kodak cartridge, this printer shut down with 43 percent of the ink remaining. Its full quantity of ink weighed 16.857 grams, and its unused ink after shutdown weighed 7.272 grams.

Kodak doesn't dispute our findings, but the company argues that our results don't tell the whole story. Roderick Eslinger, Kodak technical marketing manager, says that Kodak's in-house tests in 2007 indicated that 65 percent of its cartridge ink was used for consumer printing, while 35 percent was used to "protect/maintain optimal Kodak printer performance and document quality." Eslinger says that the remaining ink is "already factored into our industry advertising claims for consumers, and that Kodak cartridges offer "low costs and high quality yields as compared to competitors."

With a G&G cartridge, the Kodak printer shut down with 36 percent of the ink remaining in the tank. The leftover ink weighed 5.360 grams. Kodak chose not to comment on the aftermarket results.

Watch the Page Yield
Some vendors and analysts advise consumers to make sure that they get the correct page yield (the total number of pages produced with a single cartridge), rather than focusing on the amount of ink left unused in a cartridge that must be discarded. "This is the most reliable way to understand the life of a cartridge, rather than the amount of ink, or what might be left over," says Lippman.

But vendor page-yield estimates don't always match reality, as we discovered when testing printers for another PC World article, "Cheap Ink: Will It Cost You?" Using a different set of OEM cartridges and printers, we found that one HP black cartridge exceed its projected page yield (810 printed vs. 660 projected), while page yields from Epson and Kodak cartridges fell short of expectations. Specifically, Epson printed just 209 pages, far less than the 335 pages the company estimated it would produce; and Kodak generated 480 pages versus a projected page count of 540. (For a slide show comparing the quality of prints made with the two kinds of ink, see "Head-to-Head: Printer Manufacturers' Ink vs. Cheap Third-Party Ink.")

Page yields aside, we have yet to hear a satisfactory and persuasive explanation from a vendor as to why so many printer cartridges leave so much ink behind. Even if the waste amount is only a few milliliters, that unused liquid could have printed a lot of pages.

PC World's Tips for Saving Money on Printing
For additional advice on reducing the cost of running your inkjet printer, see "The Cheapskate's Guide to Printing," "Save Money on Inkjet Printer Ink," and "How to Spend Less on Printing and Get Better Results."

An earlier three-part PC World series on the subjects of counterfeit name-brand inks ("Bogus Ink Stink"), third-party ink quality ("Cheap Ink Probed"), and high ink-cartridge prices ("Why Do Ink Cartridges Cost So Much?") provides valuable historical background and additional test results for various ink cartridges.

 

This story originally appeared on PCWorld