Why is the Greenback Green?

Why is the Greenback green? The short answer is that green ink was a security feature in the mid-1900s.

In 1857, an ink was patented that could not be removed from a note without destroying the paper substrate. The underlying chemical caused the ink to be green. So, green was not an aesthetic choice. This ink became known in the banknote industry as patent green ink.

When, during the Civil War, the US Government needed its first banknotes produced, these United States Notes were produced using this patent green ink. But, this ink was only applied to the front of the notes because it was expensive.

So, why are the note backs green? The problem with patent green ink is that it bled through the paper. To cover this up, the US Treasury had the backs of their first banknotes extensively printed in a different, cheaper green.

Hence, greenbacks have green backs because the faces have patent green ink on them.

The nickname, “Greenback,” came from Union Army troops who received the notes in their pay packets. Soldiers being soldiers, they just called the notes Greenbacks, because the backs were green.

The use of green backs on these first Government bank notes started a design tradition that lasts until today.