German efficiency consultants conclude Epson ink-jet cartridges leave less ink unused

Epson has revealed that the highly-regarded TÜV Rheinland Group, which documents the safety and quality of new and existing products, systems and services for companies around the world, has concluded that Epson ink-jet cartridges are the most efficient, although the exact definition of the term 'efficient' was debated by journalists when it was presented to them.

In TÜV Rheinland's research, which was commissioned by Epson, but only on the undertaking that Epson would accept the findings of the independent research in full, several samples of ink-jet printers from all the leading brands were tested to find out how much ink remained in cartridges at the time they needed to be replaced. TÜV Rheinland explained that the research aimed to find out: "if single ink cartridges are more efficient than multi ink cartridges."

Ink remaining

In reality, the research only answered one aspect of the highly complicated issue of ink-jet printer efficiency: the amount of ink remaining in a cartridge when it's time for it to be replaced.

The TÜV Rheinland research found that substantially less ink was wasted in single ink cartridge systems than in cartridges that contained several different ink colours. All the single ink cartridge systems from HP, Canon, Brother and Epson were near or exceeded 80% efficiency. Only one multi-ink cartridge printer, Canon's Pixma MP160, got close to 80% efficiency. One single ink system printer, the Epson Stylus Photo R360, exceeded 90% efficiency.

This is encouraging news for Epson as the company has been criticised in some quarters for electronically limiting the life of their cartridges, with the suspicion being that just because the printer decides the cartridge is empty, there is actually plenty of unused ink left. Canon single ink cartridges are transparent so you can see what's left. Other manufacturers let you run the cartridges until no more ink flows and the printer can no longer print normally.

No foam

Uniquely, Epson cartridges don't use foam to contain the ink, so you can shake the cartridge to detect any ink remaining. Epson explains that while some residual ink always remains inside spent cartridges, this is necessary to prevent the print head from running dry and risking a permanent air lock. All cartridges retain residual ink, according to the TÜV Rheinland research, with non-Epson types locking up that ink in their foam inserts.

Multi-ink cartridges do waste more, but...

It does seem obvious that single ink cartridges are intrinsically less wasteful. As soon as one colour is depleted in a multi-ink cartridge, that whole cartridge must be discarded, no matter how much remains of the other colour inks. The rate at which a colour is used up is not constant, either. But it's not at all as simple as that. Ink is wasted by single ink systems as well.

Each time a single ink cartridge is replaced, ink must be forced through the print head from all the cartridges as part of the priming procedure for the new cartridge. Only HP has a system for re-cycling ink used in such 'maintenance' cycles, which also include on-demand and routine print head cleaning. The TÜV Rheinland research didn't consider this aspect of cartridge efficiency.

The question of cost

Nor did the research consider cost of ownership. Kodak's new EasyShare ink-jet printers, for example, use a multi-ink cartridge system and TÜV Rheinland found that Kodak's efficiency rating was the worst, at under 40%. However, Kodak's ink cartridges are claimed by Kodak to be the cheapest in terms of cost per print over the lifetime of the cartridge.

DPNow spoke to Hartmut Müller-Gerbes, Head of Communications at TÜV Rheinland, after his presentation. We pointed out that, while interesting, the research didn't paint the whole picture. He conceded that the cost aspect of ink-jet printer ink usage was never on the agenda, though he agreed that there was scope for extending the research in that direction if there was demand. He also admitted that the research did not measure the yield of the print cartridges, nor take in to account ink wastage through maintenance cycles. DPNow has earned an invitation to visit the TÜV Rheinland testing facility in Cologne, Germany, and if we are able to take up this invitation, we'll let you know.

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