Image Reproduction

There are many ways to reproduce an image-the internet, inkjet or laser printers for home use, large-format inkjets for banner and billboards all the way to high-end image setters used to make the printing plates for a press. Each one of these devices has a maximum quality that it can reproduce. Unfortunately, they do not all have the same maximum amount of quality. If they did we could all agree on one standard resolution for all image files. (But then, if they could all produce the same quality, either the internet would be a very slow medium or there would be no high-end prints available.)

The reason for the various amounts of reproduction quality is due to the way each device reproduces the image. Monitors reproduce all images with pixels, inkjet printers with a spray of ink, and high-end image setters with laser dots, and the quality of these devices is referred to DPI (dots per inch). After all is said and done, each device requires an image to have enough PPI to take full advantage of the devices DPI.

If we know how we intend to use our files we can follow a few “safe” rules of thumb:

• web images should be saved at 72ppi (the average quality a monitor can display)
• inkjet prints require an image resolution of about 100ppi (due to the way the ink is laid down on the sheet)
• high-end prints require an image resolution of about 300ppi (due to the way the image setters create half-tone dots).

Unfortunately, these rules are not always enough. Not all high-end prints really require that much resolution, while some (like line art) require much more; and, some inkjet printers can do wonders with lower resolution files while others require a slightly higher resolution.

This entry was posted on Thursday, February 23rd, 2006 at 1:44 am and is filed under Design. You can follow any responses to this entry through the RSS 2.0 feed.

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