What was the error on the 2009 $100 bill?

The Crease in the 2009 $100 Bill

When the new $100 bill was unveiled in 2009, it was hailed as a triumph of anti-counterfeiting technology. With its 3D security ribbon, color-shifting bell, and intricate design, it was meant to be the most secure U.S. currency yet. But behind the scenes, a subtle flaw began to surface—quite literally.

In September 2010, the Bureau of Engraving and Printing (BEP) discovered an unexpected issue: some of the bills were developing small creases during the printing process. These creases weren't just cosmetic—they were the result of paper malfunctioning under the press, folding slightly before the ink had fully dried or set. What made it worse was that this flaw hadn't shown up during the extensive pre-production tests, catching even officials off guard.

The problem wasn't widespread, but it was enough to raise concern. The Federal Reserve acknowledged the issue in an October 1, 2010 announcement, noting that the creasing occurred only sporadically. Still, it delayed the full rollout of the bill by over a year while engineers adjusted the printing process and paper handling systems.

Why did it happen? The new design used more complex inks and security features, which may have interacted unexpectedly with the high-speed machinery. The creases themselves were minor, but any irregularity in currency can fuel counterfeiting fears or cause jams in ATMs and vending machines.

Eventually, the kinks were worked out, and the improved $100 bill entered full circulation in 2013. Today, it's considered one of the most advanced banknotes in the world. But that early hiccup—a tiny crease in a sea of otherwise flawless bills—reminds us that even the most meticulous plans can stumble when paper meets machine.