Beneath the Hood: Inkjet Printers
Learn about inkjet Technology: Its advantages and disadvantages
While the typical inkjet printer may not seem like a very impressive device, there’s actually some precision technology involved that enables you print a high-quality photo print or a text document. Here’s a guide on how it all comes together when you start printing a job.
Inkjet printers can be found everywhere, from the home to the office. Models range from inexpensive home versions to the high-end models that can print A3-sized photo prints for professional use, but what makes the inkjet so popular?
For starters, inkjet printers are versatile; they offer users good photo print quality as well as acceptable text quality. They are also able to print on a variety of media such as glossy paper, cards and iron-on transfer papers. And most entry-level models are very affordable, appealing to those on a budget.
But the inkjet printer isn’t without its flaws. While the cost of the printer itself may not be very high (compared to a laser printer of a similar class), replacement ink is quite costly. When comparing the cost per page between a lower-end inkjet printer and a lower-end laser printer you may not see much of a difference, but the cost per page for laser printers drop when you start moving into the mid-range models. Unless you’re buying an entry-level inkjet printer, the cost per page will generally be lower with laser printers. Some inkjet models also produce less than sharp text, which is bad news if the bulk of your print jobs consist of business documents. And while it may go either way in terms of speed with the lower-end laser and inkjet printers, laser printers are generally faster than their inkjet counterparts.
HOW DOES IT WORK
Inkjet printers print by pushing ink through the nozzles in a print head. These small dots of ink then create an image. The more dots the printer can squeeze in a square inch (dpi or dots per inch), the higher the quality of the print. But how does the printer push the ink through the nozzles?
Contemporary inkjets use either the thermal inkjet process or piezoelectric technology. Most consumer brands such as Canon and HP employ the thermal inkjet process. For thermal inkjets, each ink cartridge contains minute chambers, and when a current is passed-through the heating element in the chambers, the ink vaporizes and forms a bubble. The formation of the bubble causes a large pressure increase in the chamber, which pushes the ink droplet onto the paper. As no special materials are required for this printer technology, the print head for thermal inkjets are generally cheaper to produce compared to the piezoelectric printers.
Manufacturers that employ the piezoelectric technology include Brother and Epson. Instead of using heat to push the ink onto the paper, when a current is passed through the piezoelectric material, the material changes shape and creates pressure, which then forces the ink out through the nozzle. Due to the nature of a piezoelectric printer, there’s less buildup of ink residue when compared to a thermal inkjet, and thus print quality is less likely to suffer.
Depending on your usage, higher dpi may not necessarily be better. For printing simple lists or even business documents, 300dpi is more than sufficient. However, dpi aside, the type of ink used will actually make a difference as well.
Inkjet printers generally use two types of inks: dye-based inks and pigment-based inks. Dye-based inks are basically colored liquids and are better at blending colors and thus produce better photographic prints. Dye-based inks also have better brightness and a broader color range when compared to pigment-based inks. However, dye-based prints are also more prone to shifting of colors and fading, which is bad news if you make a living selling prints. No one wants to have a customer return and complain about your prints fading or changing colors.
Pigment-based inks are liquids that contain particles of color suspended in them. While the fibers of the paper you print on will absorb dye-based inks, the particles in pigment-based inks sit on top of the paper, which explains the longevity of pigment-based prints. Pigment-based inks are able to produce cleaner and more precise text, while also offering better color stability and longevity for your prints.
It’s hard to beat an inkjet printer when it comes to printing photos and colored graphics.
Some printers use a combination of both inks. For example, a HP printer may use a black pigment-based ink as well as a dye-based color ink cartridge.
The Epson UltraChrome K3 series of inks are an example of pigment-based inks.