Consumers will be better able to judge the costs of printing thanks to a new international standard for cartridge performance.

Until now, printer manufacturers have used a variety of ways to measure how many pages a cartridge will print.

This means that although it has been incredibly cheap to buy some printers, estimating the true expenditure on cartridges during a printer's lifespan has been nigh-on impossible.

Not knowing has also made it difficult for consumers to decide which printer is appropriate to their needs.

In December 2002, the Office of Fair Trading (OFT) criticised the four major manufacturers, Epson, Canon, HP and Lexmark, over the lack of information available to consumers about the longevity of inkjet cartridges and the true cost of ownership.

In its report it said this lack of transparency regarding the price and performance of inkjet printer cartridges was unfair to consumers.

It said 78 per cent of consumers use only the cartridges recommended by the manufacturer, which means expenditure on these consumables over the lifetime of a printer can amount to more than double the original cost of the printer.

The OFT called on the industry to devise a standard testing method for page yield and for these results to be made available by retailers to consumers at the point of sale and in promotional literature.

It also said the cartridge manufacturers should set up webpages where consumers can compare page yield and estimate the overall costs.

This standard was meant to be in place by the end of 2003 but the OFT gave the industry additional time.

Finally, in December 2006, the International Organisation for Standardisation (ISO), in conjunction with a consortium of printer manufactures including HP, Canon, Epson and Lexmark, approved new standards for accurately measuring how many pages inkjet cartridges would print.

HP explained to Computeractive how it meets the new standard. The company takes three printers of each model and nine cartridges per cartridge model for each document yield test.

Three different document types, representative of consumer documents, are used to determine three different yields: black text and graphics, colour graphics and photo suite.

Generally, all three document types are tested on current printers, unless there are product limitations. These test files are sent from a computer to the printer for testing.

The tests are carried out in controlled conditions. Printing during tests is nearly continuous, with normal breaks for changing paper, and temperature and humidity are controlled to reflect ambient home or office conditions.

OEMs were anxious to point out that using printers differently can affect page yield.

"Stop-start printing can affect yield as the print heads use some ink in between printing jobs to clean the heads," explained Andy Forsyth, a spokesman for HP.

But it still gives the consumer an easier way to compare page yields, pointed out Chris Law, for Lexmark.

Lexmark told Computeractive the necessary information will be available for printers released this year. HP said it planned to provide this information for some printers already on the market.

There was no comment from Epson or Canon as we went to press, however HP and Epson have set up an area on their respective websites where consumers are be able to compare costs; Lexmark said its page would be ready later this month.

Also, when consumers buy an OEM cartridge or printer, the box and cartridge packaging will give the print yields so they can estimate costs they may have to pay for printing over the lifetime of the printer.

Computeractive ran a feature in issue 220 on how to cut your printing costs, which can be read by clicking here.