How do I decide which scanning resolution to select when scanning?

• The best scanning resolution depends on the purpose of the scan:
  • If you are going to print the scan, you should generally scan at 300 dpi for best results (although 180 or 240 dpi may be high enough depending on the quality and detail of the original image).
  • If your final file is for on-screen viewing (for example, on a web page or in an e-mail message), select 96 dpi for your resolution.
  If you are enlarging your image, you must increase the resolution (dpi) proportionally to maintain the resolution of your original.
  
  Higher resolution settings result in larger file sizes. For example, an 8.5 x 11-inch original scanned at 300 dpi can produce a 24MB file. The same original scanned at 72 dpi creates only a 1.3MB file. Large files take longer to process and print, so consider the practical limitations of your computer system when selecting a resolution. To keep your file size manageable, select the lowest possible resolution that gives acceptable quality.