The Federal Reserve has issued a new hi-tech $100 banknote comprising several new security features.
It includes a blue 3D security ribbon and a bell and inkwell logo that authorities say are particularly difficult to replicate.
These combine with traditional security features, such as a portrait watermark and an embedded security thread that glows pink under ultraviolet light.
The 3D security ribbon - which is woven into the note, not printed on it - features images of 100s that change into bells and move upwards or sideways depending on how you tilt the paper.
Tilting also reveals a green bell within a copper-colored inkwell to the right of the blue ribbon.
In addition, the 100 number in the bottom right-hand corner shifts from copper to green.
The redesigned banknote, which features a portrait of US founding father and scientist Benjamin Franklin, also includes raised "intaglio" printing that gives the notes a distinctive feel, and micro printed words that are difficult to read without magnification.
The 2010 design was delayed until now because of "unexpected production challenges".