The Federal Reserve Bank of New York releases a new $100 bill design every decade or so, and the latest design was released in 2013. One of the new features on the bill is a blue, 3D security ribbon. This ribbon is made up of thousands of tiny lenses that create a shifting image when you move the bill back and forth. To create this effect, the blue dye used in the security ribbon is mixed with particles that smell like peppermint. Because of this, US $100 bill smells.