How does a printer work?

Woman using a printer in a home office.
(Image credit: Getty)

For decades we’ve had them at our disposal ready to print out documents, photographs, resumes or even homework, but you still might find yourself wondering, 'how does a printer work'? 

Modern home printers most commonly come in two types: inkjet and laser, with the vast majority being the more affordable inkjet variety. Prints from both machines might look the same at first glance but the mechanics under the hood vary considerably, in this article we’ll take a look at how both inkjet and laser printers work as well as the benefits and pitfalls of each system so you can work out which is best for your home or office. 

How does an inkjet printer work?

As the name implies, inkjet printers use wet ink usually stored in replaceable cartridges, though some higher-end models use large ink tanks that can be topped up with ink when they run low. Cartridges are however more commonly used and in budget inkjet printers you’ll usually find two of them, one for black and another ‘tricolor’ cartridge which contains three colors - cyan, magenta, and yellow. Ink droplets from each are then built up on the page where they mix to build up a full spectrum of colors and tones. Higher-end premium models have extra ink cartridges such as photo black, matte black, light black, light light black, cyan, light cyan, yellow, vivid magenta, and vivid light magenta for an even wider gamut of tones.

When you print from your computer, the printer software electronically sends the document to the printer via Wi-Fi or a wired USB connection. The printer then knows exactly where to spray each tiny droplet of ink on the page as it’s passed through. Due to the nature of wet ink, you need to allow a small amount of time for your prints to dry before handling them to avoid any smudging from occurring. 

Overall, inkjet printers are very affordable as an initial purchase, though ink can rack up costs quickly, particularly if your model only has two cartridges. They are, however, very compact and don’t take up a huge amount of space, many models also have a flatbed scanner and fax machine built-in which enhances their convenience further. 

Premium inkjet printers with a wide range of ink can also deliver far superior print quality for photos compared to laser models, but this comes at the cost of speed as they’re slower. The print nozzles can also get clogged if you don’t use them regularly which can lead to unsightly streaks appearing in your images. It can also be quite wasteful if you throw away a tri-color cartridge because one of its inks has become low.

How does a laser printer work?

It probably comes as no surprise that laser printers, of course, use lasers! Inside a laser printer, you’ll find a rotating drum for each black, cyan, magenta, and yellow color, although budget black and white laser printers just contain the black toner cartridge and drum.

Each drum becomes negatively charged and a laser is then fired onto the spinning drum precisely where the toner needs to go and gives this part of the drum a positive charge. Toner from the hopper is then attracted to that area of the drum and transferred to the sheet of paper as it’s passed through.

Because you have a large drum and hopper full of toner for each black, cyan, magenta, and yellow, laser printer models are inherently much larger and bulkier than inkjet printers that use smaller ink cartridges.

Laser printers are also more expensive to buy from the offset, and replacement toner can cost around $40-60 for each color. That being said, offices usually prefer laser printers because their large footprint isn’t usually an issue, they require less maintenance as there are no nozzles that can clog with ink and they also deliver razor-sharp text, ideal for documents and PDFs. In addition, they can also be very cost-effective with an average toner drum lasting for about 2000-4000 sheets. Some companies even rent or hire their laser printers rather than buy them outright and this monthly fee covers any maintenance costs and toner, and then they pay a set rate per page printed.

The downside to laser printers is that they’re more expensive to buy outright than inkjet models, they require more space as they’re large and bulky and they use more electricity than inkjet models to using the lasers and also heat in the final step to fuse the toner to the paper, so this is all worth taking into consideration when deciding whether to go for an inkjet or laser model.

Dan Mold

Dan is Technique Editor on PhotoPlus: The Canon Magazine magazine. With over a decade writing about all things tech he’s written for a variety of publications before joining Future in April 2019 in that time working across Top Ten Reviews, Digital Camera World, PhotoPlus, NPhoto, Digital Camera and Digital Photographer.