For two thousand years and more, money - metal coins, paper notes, or electronic signals, it makes no difference - has always been counterfeited.

Almost as soon as a new banknote is issued, the first counterfeits appear. At first they are not well enough made to be a threat, but they grow ever more insidious, more closely resembling the originals in design and colour, and with the security features apparently so well copied that in some cases central banks have accelerated their schedules and replaced notes in circulation with new, more secure models.

The battle against counterfeiting, that is, is a stronger prod to technical development of the security features even than production requirements and the need to correspond to the esthetic sense of the banknote users. The ultimate purpose is always to defend the credibility of the notes as payment instruments.

The means at the disposal of the two players in this "game" - issuing bank vs. counterfeiters - are in no way comparable. The central bank employs special raw materials and special equipment, production processes and technological know-how that are inaccessible to the counterfeiter. But the counterfeiter does not actually need them: his real aim is merely to reproduce, quickly and cheaply, the overall "chromatic effect" of the note that can easily fool the person taking it in payment and induce him not to check the other security elements, evident to sight or touch, that modern banknotes carry.

The genuine banknote has to be the single piece of paper with the greatest value added of all, in which art and technology combine, with the intercession of sophisticated printing techniques and the ever-changing security features specially designed to make it easy to tell genuine from false notes and defuse the threat of counterfeits.

The battle against counterfeiting is conducted on three fronts:

  • issuing banks inform the public and people who handle large volumes of cash (e.g. bank and post office tellers) so that they are capable of detecting counterfeits,
  • police action to locate clandestine printing presses, which are often linked to organizations engaged in other crimes as well, and
  • international cooperation and information exchange among the relevant agencies.

The prevention of counterfeiting relies on special production technology.

For Italy's old lira banknotes, a particularly heavy rag paper, recognizable to the touch, and opaque even under ultraviolet light, because unlike ordinary commercial paper it was not artificially bleached.

A second key feature of these notes was the watermark, which was visible against the light. The last two issues of Italian banknotes also had two security threads: one near the watermark bearing the words "Banca d'Italia" and the second, in the centre of the note, with a bar code used for automatic sorting.

Copper-plate printing - a particularly refined technique, used for that reason for the larger denominations - permitted excellent graphic reproduction of portraits and designs that could be perceived by touch as well. In recent years letterpress printing was used for the serial numbers.

Finally, optical variable inks that change colour depending on the angle at which light strikes them made it easier to identify genuine notes.

All these security features have been incorporated in today's euro notes, which also have additional security features detectable by sorting and control equipment.