How do you spot a thieving printer? We've identified some of the leading suspects for each specific crime. But to determine whether your printer is pilfering from you, check its specs and our reviews for these warning signs.

Think you got a great deal on your printer? Think again. It's a common ploy for printer vendors to sell machines at or below their production cost--and then make their money later on with extremely high ink or toner costs. How can you tell? Do the math: Take the cost of the cartridge and divide it by the page yield--the number of pages the manufacturer says the cartridge can print. (Note that most vendors base their page-yield numbers on industry-standard testing that is designed to represent real-world usage. However, the page yields you obtain may vary, depending on what you actually print.) Some vendors make their page yield information easy to find online (thank you, HP!), while others bury it (we're looking at you, Canon). The cost per page for the printer's ink or toner does not reflect other printer costs, of course, such as those for an inkjet's special paper or for a laser's belts, drums, and other longer-life consumables.

We collected cartridges prices and vendor page yield information for a number of printers. From them, we determined that the following costs per page for black-and-white and four-color pages for inkjet and laser printers are about average.

Inkjet printers:Plain black text: 4 cents to 5 cents per pageSimple four-color page: 12 cents to 14 cents per page