Surprising Facts About Money You Didn’t Know Before
6. Color-shifting inks
Most countries of the world use such inks to print their banknotes. The ink reflects the light and changes its color with the angle. For example, the number 50 on a $50 bill can be either copper or bright green. The technique can’t be copied and is very hard to fake because there are only a few companies in the world that are permitted to manufacture such color-shifting inks.
