Modifying Printed Checks; Lithographic Printing; Impact Printing - Xerox 6100BD - Phaser Color Laser Printer Fundamentals

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Modifying printed checks

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• Selecting checks with a structured background pattern. This
type of background accentuates the pattern change that
results from tampering. Random check backgrounds may
camouflage damage due to alteration.
• Using "fugitive" inks, which run when a solvent is applied. A
water soluble ink shows any attempt to loosen and remove
paper fibers attached to a dry ink image.
The ease with which a tamperer can modify an image, either
chemically or mechanically, depends on how intertwined the
printing inks are with the fiber of the paper with which the inks
have been in contact.
The following printing technologies react in different ways to the
different tampering methods.

Lithographic printing

Lithography is difficult to modify. The inks are liquid when applied
and soak into the fibers of the paper. The flow of the ink through
the paper fibers makes the edges of the characters indistinct.
If a nonabsorbent paper is used, or a paper with an ink hold-out
layer, the image may sit on the top layer of the paper, making it
easy to erase. The deeper the ink soaks into the paper, the more
paper fibers must be disturbed to remove the ink, and the more
noticeable the alterations are.

Impact printing

The two types of impact printing are letterpress and ribbon ink
transfer.
• Letterpress: This method is not recommended for printing
variable data required for check applications.
• Ribbon transfer: This process involves either fabric or mylar
ribbons.
– The fabric ribbon ink is semi-liquid. An example is a fabric
typewriter ribbon or printer ribbon that leaves ink on your
hands when you touch it.
Generic MICR Fundamentals Guide