Determining Scanning Resolution
This is the most difficult area of scanning to understrand because there are so many variables- and things are changing all the time. Sorry.
I have created a simple table to give you a few suggestions:
| Resolution | Use | Why | |
| 72 DPI | web page and multimedia production | computer monitors typically resolve to only 72 dots per inch | |
| 240 DPI | Printing on a 720 DPI inkjet printer (such as Epson) | An inkjet printer prints with three colored jets: Cyan, Magenta and Yellow (CMY) Each color jet prints at 240 DPI for a combined resolution of, 3 X 240 = 720. There is also one black jet (K) to fill in the shadows. |
|
|---|---|---|---|
| 300 DPI | Printing on a typical laser printer | This is the finest dot size created by some laser printers. | |
| IRIS continuous-tone printer | The Iris is an inkjet printer that creates near-photographic quality images. This is due to it's ability to print different densities of ink rather than scattered dots, like an ordinary inkjet printer. | ||
| Higher DPI | Creation of halftones for offset-printing | In order to arrive at the desired number of color variations and detail clarity, many factors are involved. Scan at twice the halftone screen (LPI=Lines Per Inch) . Example: for 133 LPI, scan at 266 PPI (pixels per inch). Output resolution is another story, based upon this formula: |