To calculate page costs you take the cost of the cartridge and divide it by the page yield. This will give you the cost per page based on 5% coverage. If you think of a standard business letter with an address panel, dear sir and 4 lines of small plain text with a signature at the bottom that will give you an approximate idea of 5% coverage. Anything more than that and you will see a significant decrease in the amount of pages you will receive from your printer or toner cartridge before it runs out.

Page yield of printer cartridges are tested using a method called ISO/IEC 24711 for ink cartridges and ISO/IEC 19752 for mono toner cartridges.

The method for ISO/IEC 24711
The test is conducted using the printers default setting for plain paper, sets of 5 pages are printed until the cartridge reaches the end of its life which is when the printer either signals the ink is empty or the test papers become lighter or show discolouration. A total of 9 cartridges are to be tested on 3 different printers under controlled temperature and humidity conditions to be similar to the home or office.
For colour ink cartridges the same test is performed on a 3-colour composite page, a combination of cyan, magenta and yellow are use. Colour page yield for individual colour cartridges are determined by using the average yield which is gained by continuous print of all the individual colour cartridges. For combined colour cartridges the yield is determined by the 1st colour to become empty.

The method for ISO/IEC 19752

This test is performed using the printers default plain paper setting, a standard test page of approximately 5% coverage is used during almost continuous printing which is only stopped for adding paper. A total of 9 cartridges are tested across 3 different printers under controlled temperature and humidity conditions to be similar to the home or office and the average yield is calculated.
Printing continues until the cartridge reaches its end of life which is determined by the printer indicating the toner is empty or a decrease in the quality of the print.

The method for testing photo cartridges is different; HP has published details on how they test their cartridges which is as follows.
The tests are conducted using the photo printers default photo paper setting. 9 cartridges are tested across 3 different printers; the colours tested are standard colour, photo colour and grey. The test pages use images from the typical amateur photographer. The tests are conducted under controlled temperature and humidity conditions which almost continuous printing only being paused to add more paper.
Printing continues until the cartridge reaches its end of life which is determined by the printer indicating the ink is empty.

Most entry level printers are sold extremely cheaply by manufacturers.  In fact when you buy a $49 printer the chances are you’re getting it at cost, with just a few freight charges added.  I see customers walk into my shop and when told that their cartridges will cost them double what the printer cost in the first place they get furious.

They say it’s cheaper to just buy a new printer.  Well this is true.  You could just buy a printer and throw it out when it’s out of ink.  Then you could buy a new one and start again.  But that is a false economy.

The cartridges that come in a new printer are not full.  They are what manufacturers call Starter, or Introductory cartridges.  This means the manufacturer gives you a printer and cartridges so that you’re able to get a taste of what the printer can do and then buy full cartridges at the retail price.

It’s the gilette business model.  Give away a razor, build a brand following and then charge for replacement blades for the rest of your life.

Stay tuned for part 2!