Scientific American 07-24-07 Counterfeiters Beware: You Left Your Signature A new technology sniffs an ink's chemical signature in seconds By Sourish Basu Thinking about forging a check? Might want to reconsider. It just got a whole lot easier to track you down. Using a new application of a recent technology, forensic specialists can figure out when a check was signed, what pen was used and even the origin of the ink used to sign it. Until now, ink could only be traced if a piece of the document were soaked in certain solutions. But the new method, aptly dubbed DART (for direct analysis in real time), can read the ink chemistry off the paper in a few seconds, without leaving any evidence that the paper was examined. The DART technology, commercially marketed by the Japanese company JEOL Ltd., is a few years old and is currently used by agencies like the FBI to identify minute amounts of toxins. Now, chemists at Ames Laboratory and Iowa State University have adapted this technique to analyze ink samples through mass spectroscopy.