Microtek ScanMaker 6100 Pro User Manual page 100

2. When the Descreen menu comes up, select the screen for your
needs, or choose Custom to set your own descreen options.
When the Descreen dialog box comes up, enter a value
that best corresponds to the dot quality of the original in
which the moiré is to be removed. You may use a screen
finder to measure the print screen lpi. Please contact
your local print shop for more information on how to
obtain a screen finder.
Set a value from 50 to 85 if the original image has a coarse
dot pattern, as in images taken from a newspaper.
Set a value from 100 to 133 if the original image has a fine
dot pattern, as in images taken from a magazine.
Set a value from 200 to 250 if the original image has a very
fine dot pattern with a near-photographic quality, as in images
taken from a high-quality art magazine.