Security Features of a 20 dollar bill
These are some of the Security Features of the US Twenty Dollar Bill
1. Microprinting under the border to the left of Andrew Jackson's portrait says "THE UNITED STATES OF AMERICA 20 USA 20 USA"
2. Microprinting around the first three letters of each line to the left of the Treasury Department seal repeats "20 USA"
3. A watermark embedded into the paper the bill is printed on depicts a portrait of Andrew Jackson that is identical to the one printed on the face of the bill.
4. The 20 on the bottom left of the front of the bill is printed using color-shifting metallic flecks. Changing the angle at which the bill is held will change the apparent color of the printing from gold to green. Additionally, the eagle and shield image is printed with an embossed sparkly ink.
5. A mylar security thread runs vertically 17mm from the edge of the paper. This strip will glow green when exposed to UV light and has the microprinting of "USA TWENTY" along with a US Flag. Instead of stars, the miniature flag has the number 20 printed.
6. The bill is printed using an engraving process that is able to reproduce extremely fine lines (first image). When the bill is printed using a commercial inkjet (second image) or laser printer (third image) the fine lines are obscured and colored ink spray is clearly visible under high magnification. The images were taken at 100x magnification.
7. The back of the bill is printed with two types of optically indistinguishable ink. Under infrared light (second image), a vertical strip of printing on the left side of the note disappears. The inks used to create the bills also have varying magnetic properties. These two features are extremely difficult to reproduce and allow advanced commercial scanners to identify counterfeits.
8. The yellow 20's printed on the back are placed to form a constellation that assists anti-counterfeiting technology in copiers and computer imaging software in identifying a scanned image as currency. This constellation, called EURion, is also featured in the bank notes of several other countries.