How can I tell which scanning resolution to use for the best results?

• Resolution refers to how many dots per inch (dpi) or dots per centimeter (dpcm) your image contains. The best resolution for a scanned image depends on the type of image you're scanning and the final output device. As a rule of thumb for most images (except line art), use a scanning resolution that is approximately one third of your output resolution. For example, use a scanning resolution up to 100 dpi with a 300 dpi laser printer, and up to 200 dpi with a 600 dpi laser printer. For 1440 dpi ink jet printers, such as the EPSON Stylus Color series, use a scanning resolution of up to 300 dpi. Try a scanning resolution of 240 dpi for 720 dpi printing. Here are some recommended settings for different types of scans.
  
  

  Image Type	Scanning resolution
  Photograph	300 dpi
  Text with images	400 dpi
  Film or slides	300 to 3200 dpi
  Line art	300 to 3200 dpi
  Image for web	96 to 150 dpi
  Text for OCR	400 dpi
  Newspaper	400 dpi
  Magazine	300 dpi