Xerox DocuPrint 100 User Manual page 72

Magnetic ink character recognition (MICR)
Transmitted light
Reflected light
6-6
To use the comparator with transmitted light, place the bottom of
the comparator on the document and hold the document in front
of a transmitted light source. This allows the light to be
transmitted through the document. This is particularly useful
when checking for voids and verifying the edges of the
characters.
Using the comparator with transmitted light is the most accurate
method of verifying character quality, as transmitted light tends
to make the line more narrow and make spots appear smaller.
To use the comparator with reflected light, place the bottom of
the comparator on the document and hold the document in front
of a reflected light source.
Using the comparator with reflected light is the most accurate
method of checking for spots.
System Overview Guide