Beware of cheap imitations. Europe is about to be inundated with strange money and criminals will exploit the confusion by releasing a flood of counterfeit euros.
It should become clear in the coming weeks that it was wise to keep the new notes under wraps. But while the extraordinary security measures have made it harder for forgers to print good copies, the public could also find it more difficult to spot a fake.
"The most vulnerable time is obviously at the launch," said Derek Porter, head of the forgery unit at Europol in The Hague which is co-ordinating the fight. It is a task complicated by 12 countries each producing the notes.
Mr Porter, a Scot, has been trying to keep one step ahead of the forgers for two years.
For the European gangs and those operating further east or in Latin America or West Africa, the new currency presents a wonderful opportunity. Fake notes have already been peddled by conmen going from house to house posing as helpful bank staff.
Since hardly anyone has seen the new notes, the forgeries do not need to be very good. Even photocopies may fool some people.
The European Central Bank claims its money is forgery-proof, and the experts do not entirely disagree.
Every known security feature has been built into the new notes, including holograms and shades of colour difficult to reproduce.
Wim Duisenberg, president of the European Central Bank, said: "Citizens can be confident that the euro is a safe currency and one which few residents will have the misfortune ever to see counterfeited."
Mr Porter said: "The euro banknotes are far better protected than any of our national currencies. It would be naive though to suggest that they are counterfeit-proof. Each security feature could be replicated."
The vulnerability of the new currency was shown three years ago when a hologram printing plate was stolen during a flight in Germany.
Security vans delivering the new notes to banks have been hijacked across Western Europe in the past months. By now their contents could be in expert hands in Bulgaria or other centres of forgery.
The fake euros already discovered are primitive reproductions, often using nothing more elaborate than a computer scanner and a laser printer. They are likely to appear in large numbers at the same time that the European Central Bank launches its notes.
"I'd expect to see counterfeits in early January," said Mr Porter. "Particularly in the first weeks, they should be of the quality that people would be able to detect."
The next generation of counterfeit notes will be harder to spot. The majority of fake US dollar bills are produced by offset printing.
The forgers start with a high-resolution photograph of the note, which is then etched on to printing plates. A combination of silkcreen printing, computer tricks and industrial machinery can conjure up astoundingly close imitations. The hologram and watermarks can also be copied.
Imperfections will creep in, though, allowing Mr Porter and his colleagues to distinguish between the work of various counterfeiting gangs, chart their activities and, ultimately, make arrests.Reuse content