What the Grayscale scanning mode is good for?
Poor-quality documents are best scanned in grayscale color mode with a resolution of 300 dpi. When scanning in grayscale, the program will select the optimal brightness value automatically. With this option, no data loss occurs.
The grayscale scanning mode retains more information about the letters in the scanned text to achieve better OCR results when recognizing documents of medium to poor quality.
More information about Scanning Tips can be found in online help.