How do I decide which resolution to select when scanning from Epson Scan?

• The best scanning resolution depends on the purpose of the scan:
  • If you are going to print a scanned photo or document, you should scan at 300 dpi for best results.
  • If your final file is for on-screen viewing (for example, on a web page or in an e-mail message), select between 72 and 150 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.