Tampering Methods; Chemical Tampering; Mechanical Tampering - Xerox 6100BD - Phaser Color Laser Printer Fundamentals

Tampering methods

Chemical tampering

Mechanical tampering

Generic MICR Fundamentals Guide
There are several methods by which data on a check may be
altered. The security papers on which negotiable documents are
printed are designed to thwart these forms of tampering.
Many inks can be affected by particular chemicals, making
chemical alteration of checks possible. These chemicals could
be some combination of solvent and bleach. Certain inks can be
bleached without materially affecting the paper stock. Other inks
can be selectively removed without affecting the rest of the
image.
Select check stocks that contain materials that make altering the
printed transaction information difficult. For example, if ballpoint
pens will be used to complete the check, the paper should
contain indicators for ballpoint ink solvents. If organic dye based
inks, which are susceptible to bleaching, will be used, select
papers containing a bleach indicator. (Because dry ink images
are encapsulated in a plastic resin, they are almost impossible to
bleach.)
Check stock must also remain compatible with the MICR printing
system on which it is used. Some chemical security features can
damage printer subsystems. A marginally effective security
feature could actually degrade overall document security.
Mechanical alterations include erasing, picking ink out of a
document, and scraping to remove sections of the original
document. The part of the image that is removed is replaced with
a section that looks similar. Mechanical alterations are often
attempted on xerographic images.
Ways to discourage this kind of alteration include:
• Repeating critical information at several locations on the
document. This turns a simple change of vital information into
an extensive modification of large areas of the document.
Security
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