Printer DPI Is Dots Per Inch
Printers print by applying ink or toner onto the paper. Inkjets use nozzles that spray tiny drops of ink, while laser printers melt dots of toner against the paper. When more dots are squeezed into a square inch, the resulting image is sharper. A 600 dpi printer squeezes 600 dots horizontally and 600 dots vertically in every square inch of the sheet. Some inkjet printers have a higher resolution in one direction, so you might also see a resolution like 600 by 1200 dpi. Up to a point, the higher the resolution, the crisper the image on the sheet.
Optimized DPI
Printers can place dots of different sizes, intensities, and shapes onto the page, changing the way the finished product looks. Some printers are capable of an optimized DPI print process, meaning their printheads optimize the placement of ink drops to improve the print quality. Optimized DPI occurs when the paper moves through the printer in one direction more slowly than usual. As a result, the dots overlap somewhat. The final result is rich. However, this optimized technique uses more ink and time than the printer’s standard settings.
What’s Good Enough?
For a letter or business document with graphics, 300 dpi will look fine. If it’s a handout for the board of directors, 600 dpi does the trick. For the average photographer, 1200 dpi is excellent. These specs are within reach of most printers on the market. When a printer prints above 1200 dpi, it’s nearly impossible to see any difference in the prints. There are exceptions. Professional photographers who want a higher resolution should look at 2880 by 1440 dpi or higher.
Ink Makes a Difference
Resolution is more than DPI, however. The kind of ink used can override the DPI numbers. Laser printers make text look sharp by using a toner that doesn’t bleed into the paper as the ink does. If your primary purpose in buying a printer is to print black-and-white documents, a monochrome laser printer produces text that looks crisper than that from a high-resolution inkjet printer.
Use the Right Paper
Papers optimize the differences between printers and create excellent images no matter what DPI your printer is capable of producting. Plain copy paper works well for laser printers because nothing is absorbed. However, inkjet inks are water-based, and paper fiber absorbs the ink. That’s why there are specific papers for inkjet printers and why printing a photo on plain paper produces a limp, wet picture. If you’re printing an email, use cheap copy paper. If you’re developing a brochure or flyer, it’s worth investing in the right paper.
