Scan Modes / Rules of Thumb
Note: The below table is a good "rules-of-thumb/starting point" on how to use/think about Scan Mode vs. Resolution dpi.
Types of Scan
Descriptions
Scanning Resolution
Scan Mode
Color Photo
Scans color photos.
300 dpi
True Color
Text/Lineart
Scans documents.
Black and White
Web Image
Scans images for web pages.
72 dpi
216 Colors (256 Colors)
Printed Matter
Scans printed documents.
150 dpi
Descreen at 133 lpi