Canon iR C6800 Series Service Manual page 904

Chapter 13
13.3.2.3.6 Coarse Image in a Solid C Original
0006-1405
Cause
When a solid C original is used, the machine will faithfully reproduce any uneven surface of the original
communicated by its reader unit. Moreover, the machine's controller possesses characteristics that tend to amplify a
minute difference in an area of high density, causing any change in an area of a solid C original to be amplified and
its print to show a coarse image.
F-13-19
13-32