Reference Book
mathematical laws. They may haveshine through effect that create complete
picture from sections on the front and on the reverse side of the bank note.
Microprinting:-Tiny characters, words, or phrases printed which are usually
not visible to the naked eyes. Microprinting is difficult to be reproduced by
counterfieters.
Colour shifting:- Images or numbers printed that change from copper to green
when viewed in different angles. This effect is created by adding metallic
flakes to the ink.Security ink
Security printing ink can be divided into two categories: Anti-duplication
security inks and Anti-alteration security inks.
Anti-duplication security inks:-are designed to prevent unauthorised
copying or duplication of documents. They provide usually covert features
for authentication such as UV fluorescence or reactivity to heat, metal,
UV, IR light etc. These features cannot be duplicated digitally or by
photocopying.
Anti-alteration security inks:-These inks provide indications of tampering
such as discolouration upon exposure to water or chemicals, or distruction
of the background upon erasure.
Numbering with MICR ink:- MICR or magnetic ink character recognition inks
contain ferro magnetic particles and they are machine readable which provide
an excellent method for machine processing of large number of cheques or
bank notes and at the same time as a counterfeit deterrent.
Security paper:- The major distinguishing paper attributes for security printing
is the fact that they contain a mixture of multiple overt (public security features
that are visible with unaided eye - eg: watermark, security thread), covert
(feature that are not easily visible - eg: paper fluorescence) and forensic features
(requiring advanced knowledge and special instrumentation for verification).
Currency printing :- Bank notes are printed on specially tough rag based paper
produced under conditions of high security. It contains its own water marks
which are different in design and position for each denomination. Some bank
notes comprises more than one layer of paper which enables metal or plastic
strips and other devices to be incorporated. To aid identification and avoid
forgery complicated line patterns, microimages, or secret patterns are also
included.