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

• The best scanning resolution depends on the purpose of the scan.
  
  Before you select the scan resolution, you should consider whether you will enlarge the images, and if so, whether you will enlarge them as you scan or after you scan. Follow these guidelines:
  • You will not enlarge the images.
  
  If you will scan the images at 100% size or smaller and will not enlarge them later, accept the Resolution setting selected by Epson Scan.
  • You will enlarge the images as you scan them (increase the Target Size setting).
  
  If you will enlarge the images in Epson Scan so you can use them at a larger size, accept the Resolution setting selected by Epson Scan.
  • You will scan the images at their original size, but then enlarge them later in an image-editing program.
  
  If you plan to enlarge your images later in an image-editing program, you need to increase the Resolution setting to retain a high image quality. Increase the resolution by the same amount you will increase the image size. For example, if the resolution is 300 dpi (dots per inch), and you will increase the image size by 200% later, change the Resolution setting to 600 dpi.
  
  Note: 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 print quality.
  If you are scanning at 100% or reducing the size, select your Resolution based on how you will use the scanned image:
  • E-mail or view on a computer screen/post on the web: 96 to 150 dpi
  • Print or convert to editable text (OCR): 300 dpi
  • Fax: 200 dpi