Inside the Springfield plant, where the air is heavy with a smell like oil paint, are thick dark-green and black inks, stacks of metal barrels with solvents and oils, giant mixers to combine liquids and pigments, and large tubs of colored powders with recipes attached to the sides. Scientists in lab coats scurry around.
The inks are made from as many pigments as possible to make them complex, says plant manager Richard Overkamp. The company also makes an infrared ink from a transparent pigment. It looks like regular green ink to the naked eye but is invisible under infrared light because it reflects only light waves invisible to the human eye.
One security feature on the upcoming $100 bank note is a “color-shifting ink”—the trade term is Optically Variable Ink—on a small number 100 to the right of the Franklin portrait, which shifts from copper-colored to green when it’s tilted. That ink is made from a thick translucent paste mixed with high-tech microscopic flakes. The flakes contain layers of chrome, magnesium fluoride, and aluminum, which reflect different wavelengths of light, causing the color to shift at different angles, says Thomas Classick, technical director at SICPA.
Because a color copier or scanner reproduces only at one angle, it can’t replicate the color-shifting effect. The bureau uses other security features, such as a thread that glows pink when illuminated by ultraviolet light. A thread with the letters USA and the numeral 100 will appear on the new $100 bill. Additional features are kept secret for use by Federal Reserve banks. They might include electromagnetic fingerprints, which Classick says are detectable only by multimillion-dollar machines in the central banks.
Cracking anti-counterfeiting technology usually takes crooks just a generation, according to Mihm, the University of Georgia history professor: “I’m not aware of any anti-counterfeiting technology that has lasted more than 20 years. Counterfeiters have always caught up. When anti-counterfeiting technology comes out, it puts a stop to counterfeiting until someone finds a way around it.”
Mihm thinks would-be counterfeiters of the new $100 bill are already angling to get their hands on the Motion technology: “They’ll reverse-engineer it and figure out how to make it.” He says adding new technology to a bank note is often viewed as an easy solution, but it can actually be more dangerous: “If counterfeiters can crack the code of the technology, they can produce a much better facsimile or imitation than they could while working in old-fashioned ways.”
Hipschen worries about the loss of the human touch with the move to digital engraving. Each engraver makes and sharpens his or her own tools, so that one might make more of a ragged edge when going around a turn or an angle. “The nuances are very subtle; if you lean a tool one way or another, you will have a different quality,” he says. The artists’ individual styles may not be visible to the untrained eye, but a forensic bank-note specialist can find the differences.
“You can recognize who has done an engraving by the dots and dashes,” Hipschen says. “If you are working in someone else’s style, it looks forced, not natural or correct. You can make a very accurate reproduction, but they are never quite the same.”
Adding technology to bank notes dares counterfeiters to create forgeries with computers rather than artistry, Mihm says: “It’s partly the challenge that seems to invite people to do this. Putting out the new $100 is like saying, ‘Bring it on. Hit us with your best shot.’ ”
This article first appeared in the October 2010 issue of The Washingtonian.