Exelgrams
Exelgrams are a kind of hologram and is almost impossible to fake
Exelgram is a kind of hologram, a picture made by mixing images created with laser beams, and printed on metal foil. an exelgram image printed on a bank note changes colour, or shows a different picture , as it is moved in the light.
exelgrams were invented in 1992 by Robert Lee of the CSIRO. Exelgrams are almost impossible to fake and are now used on bank notes in many other countries.
