The new US currency designs are the first major currency change since the 1920's. One of the major drivers of this redesign was to incorporate new security measures to defend against an onslaught of counterfeit currency produced by relatively cheap home printing and scanning technology. Here's an overview of the anti-counterfeiting features in the new US currency:

  • Each of the new bills has a watermark to the right of the portrait, visible on both sides of the bill. Holding it up to a light will let you view the watermark, which is an image of the portrait on the bill.

  • Each bill contains an embedded security thread, which may be located either to the left or the right of the portrait. You can see the thread by holding the bill up to a light. The thread reads "USA" along with the denomination of the bill, plus a small United States flag. Also, the thread glows under UV light. The thread for each denomination glows a different color, for example the thread in the $10 bill glows orange.

  • Portraits are larger and more detailed, thereby making them more difficult to duplicate accurately.

  • Every bill except the $5 note has color-shifting ink in the bottom-right corner of the front of the bill where it shows the denomination. The ink is green when viewed straight on, black when viewed from an angle.

  • Microprinting can be found at different locations on each bill. On the $10 note, the "10" in the lower left of the front has the word "TEN" printed over and over in extremely small print. It also has "The United States of America" printed just above Hamilton's name, under his portrait.

  • Bills now have fine line printing paterns at different locations. Behind the portrait, there are extremely fine, wavy lines that are difficult to duplicate. When copied they turn splotchy or create new patterns.

  • Like the old bills, the new bills have embedded red and blue fibers in the paper.