New background color adds an extra layer of complexity for counterfeiters.
Icon uses special ink that is hard to reproduce.
Ink appears either copper or green, depending upon the angle at which the bill is viewed.
The first $20 bill was introduced in 1861. Back then, $20 was about the monthly wage for manual laborers.
Each new $20 bill costs 50 to produce, compared with 40 for the old bill.
The average $20 bill lasts three years.
There are 4.9 billion twenties in circulation. Arranged end-to-end, that's enough to circle the earth nearly 19 times.
An ATM can hold up to 7,500 bills, or $150,000 in twenties.
The $20 bill is the most counterfeited in the U.S., while the $100 is most counterfeited abroad.
The first time a color other than black or green appeared in the bill was in 1905, when gold ink was briefly used in the printing.
