Measuring Yield: Inkjet Printers

Viable comparison of ink yields requires the use of a standard approach to yield measurement across the printing industry. In the case of monochrome laser printers, a standard exists - the ISO/IEC 19752 monochrome toner cartridge yield standard - established by the International Organization for Standardization (ISO). HP is participating in ISO's current efforts to create a yield measurement standard for inkjet cartridges and printers. Until an inkjet standard is established, HP will continue to use its own robust yield testing methodology. Many aspects of HP's inkjet methodology are similar to the key elements in the ISO monochrome toner cartridge yield standard.

With HP’s original testing methodology, three different document types are used to determine three different yields: (1) black text and graphics, (2) colour graphics and (3) a photo suite. Generally, all three document types are tested on current printers, unless there are product limitations. For example, printers designed to print only 6x4 photos are tested only on the photo suite.

• Typically, three printers of each model are used for each test.
• Typically, nine cartridges per cartridge model are tested for each of the black, colour and photo yield test.
• The specific test documents are representative of consumer documents. Test photos are representative of typical subject matter for amateur photographers.
• Test files are sent from a computer to the printer for testing.1 Printing during tests is nearly continuous, with normal breaks for changing paper.
• Temperature and humidity are controlled to reflect ambient home or office conditions.

HP also uses clearly defined criteria for determining when a cartridge reaches its end of life, a critical component for accurately calculating yield. For some printers, an on-screen message indicates "out of ink". For all other printers, a visual inspection is conducted for the discoloration typically observed when inkjet cartridges are running out of ink. End-of-life determination includes confirmation of the out-of-ink status by weighing each cartridge and comparing the result to the original cartridge weight.

While today customers sometimes compare cartridge ink volumes in millilitres, this is not a reliable indication of the relative number of pages that can be printed. HP recommends that customers look for yield, rather than millilitre, information when comparing printers and cartridges, because printers from different manufacturers vary in efficiency and the amount of ink they use to print a page. In fact, even two printers from HP that use the same cartridge can produce different yields, depending on the type of printing for which the specific printer is optimised. Specific yields for many recently introduced HP printers can be found at this website.

Even when standards are in place, yield information should still be used with care. For example, all inkjet printers use some ink before printing begins if the printer has not been used in a while or when a new cartridge is installed, to keep the ink flowing smoothly and the nozzles clear. Some printers use a lot of ink for this process, while others are engineered to use very little. Inkjet cartridge yields quoted by manufacturers and product reviews today are typically measured by printing continuously until the cartridge is empty. The proposed ISO standard also uses continuous printing. Since there is no break in printing, the ink used between jobs in everyday printing is not considered. These yields provide a useful baseline for comparing products but do not give a complete picture. Much as city and motorway driving results in different fuel consumption and fuel economy for different vehicles, customers will experience different page yields based on the efficiency of their printer and their actual usage. All HP printers are designed for efficiency to save you ink and money. Click here for more information on printer efficiency differences.

¹ Copy mode yields differ from print mode yields.