When one looks closely at the famous painting A Sunday Afternoon on the Island of La Grande Jatte by Georges Seurat you can see the basic principle behind the modern inkjet printer. Seurat excelled in the painting style known as pointillism, which is the creation of a cohesive image from a multitude of small dots of color. It is the same idea you can see at work in modern newspapers. If you look closely you can see the photos printed on the front page are constructed with thousands of tiny dots clustered closely together.

The modern inkjet printer works on exactly the same principles. Using miniscule nodules on the printer cartridge head your inkjet printer can make images of stunning clarity and vibrancy. So clear in fact that it might be hard to see the individual dots without a magnifying glass. Most modern inkjet printers create dots between 50 to 60 microns wide. How small is that? For a good comparison look at an average human hair, at its widest it will only be 70 microns in diameter.

How does an inkjet printer cartridge make such tiny dots? The key is the print head, the small rectangular area at the base of your printer cartridge closest to the paper itself. The print head is the most precise and the most active part of your printer. It's for this reason that it is usually attached to the ink cartridge, so as to assure it gets replaced when it has been used to the maximum of its potential. In the majority of inkjet printers the print head uses a tiny heating element to warm the ink, causing it to expand and create a microscopic bubble. Quite quickly the bubble bursts, forcing ink out of the print head and creating a tiny vacuum which draws more ink out of the cartridge reservoir. As you might imagine all of this happens quite quickly and on an almost unobservable scale.

Alternatively, Epson printers achieve ink application to the paper is through the manipulation of piezoelectric crystals which change orientation through the application of an electrical charge. By aligning the crystals tiny holes appear to allow the warmed ink to pass from the printer head onto the paper. This allows for a very precise application of very small ink droplets.

The average print cartridge can deliver 5,000 drops of ink per second, traveling across the breadth of a piece of A4 paper in the same amount of time printing one line of pixels as it goes. The average inkjet printer can make a full color printed page in less than one minute, with the ultimate top speed of any printer defined by the number of dots per inch (DPI) it is designed to deliver. The higher the DPI the more microscopic nodules can be found on the print head and consequently the more dots that can be printed with one pass.

Many inkjet cartridges can contain more than one color of ink. Usually this means the average consumer printer can function in full color capacity using only 2 ink cartridges; one for black ink and one for a combination of basic color elements.

As with any piece of sufficiently small and exceedingly complex technology there is a chance for malfunction or error but in the case of the inkjet printer cartridge problems rarely occur. Despite the fact that many functions are taking place at a high rate of speed the basic mechanics are relatively simple. This reliability and continuing high level of print quality is why inkjet printers continue to be so exceedingly popular among both personal and business consumers.