Counterfeit Combat: Hardest Notes to Fake

In the United States alone, there's an estimated $70 million in fake currency floating around. Fortunately, as the technology counterfeiters use improves, so does that of authentic bills.All across the globe, experts are devising high-tech methods to combat counterfeiters. Color-changing ink, special polymers and holographs are just some of the innovative technologies incorporated into today's banknotes. In 2007, the International Association of Currency Affairs began picking the best new counterfeiting technologies and tactics. They'll award this year's winners at the 2010 Currency Conferece in Buenos Aires in early May.Click ahead to see some of the world's currencies that are most impervious to fraud.Posted: March 30, 2010Source: Courtesy of PopSci.com

Courtesy Photo: PopSci.com Judged Best New Bank Note, this bill is the first to use a security thread that is visible on both sides. The thread has distinctive markings and is transparent, so additional security features underneath are clearly visible.More from PopSci.com:Building Better MoneyCracking the Poker Face: Your Eyes Betray the Numbers on Your Mind

Courtesy Photo: PopSci.com A runner-up for best new bank note, this bill is made of layered plastic polymer that changes colors as the bill is tilted—nearly impossible to replicate with home equipment. A transparent window makes it even harder to fake.More from PopSci.com:Building Better MoneyCracking the Poker Face: Your Eyes Betray the Numbers on Your Mind

Courtesy Image: PopSci.com Another runner-up for best new bank note, the 1,000 Kronor incorporates unique watermarks and is the first note to use the microlens strip, similar to the one that will be implemented in the new US $100.More from PopSci.com:Building Better MoneyCracking the Poker Face: Your Eyes Betray the Numbers on Your Mind

Courtesy Photo: PopSci.com Raised ink, such as the lettering seen in this close-up, gives this bill a distinctive texture. Elsewhere, images of a horse printed on both sides of the bill line up perfectly. Both features are difficult to fake with home equipment.More from PopSci.com:Building Better MoneyCracking the Poker Face: Your Eyes Betray the Numbers on Your Mind

Courtesy Photo: PopSci.com Nepal's 10-rupee note includes a clear polymer window—difficult or impossible to replicate with regular paper stock—and thin metallic threads blended into the paper.More from PopSci.com:Building Better MoneyCracking the Poker Face: Your Eyes Betray the Numbers on Your Mind

Courtesy Photo: PopSci.com Bills include raised lettering to give the bills a distinctive texture and are printed with inks that are only visible under ultraviolet light.More from PopSci.com:Building Better MoneyCracking the Poker Face: Your Eyes Betray the Numbers on Your Mind

Courtesy Photo: PopSci.com The newest British £20 notes include a prominent holographic strip. The image on the strip alternates between a pound symbol and the figure "20" when the bill is tilted.More from PopSci.com:Building Better MoneyCracking the Poker Face: Your Eyes Betray the Numbers on Your Mind

A tough guy from Chicago’s South Side finds his way off the streets and into a life of crime. Art Williams Jr. prints millions in fake dollars. Episode 46 of American Greed profiles the case of the counterfeiting craftsman.Premieres Wednesday, March 30th 10p | 1a ETReview the Case FileSlideshow: Hardest Notes to FakeSlideshow: Combatting Counterfeit Bills

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