Epson ES-1200C - Manual (Page 77)

8 bits 2 bits 1 bit
To reproduce an image of more than 2 bits/pixel/color the
output device should be capable of producing the same tones.
Many displays and printers cannot do this and are limited to
monochrome without gradations, or to 8 or 16 or 256 colors.
The data format chosen also affects the amount of data
necessary for scanning and storing an image. The larger the bits
per pixel value chosen, the larger the amount of image data
becomes.
One of seven brightness levels can be chosen for scanning.
Medium is the normal setting.
A-6 Appendix