GREENBACK?

The US currency, well the notes anyway, are always referred to as the greenback, and as daughter #1 has predictably just run out (the good old line, I don't know what happened because I've been writing all my withdrawals down), I've been pondering the ol' greenback and why all those notes look exactly the same in your wallet. Our pretty plastic notes here in Australia are so easy to differentiate - the lobster (20), the blue swimmer (10), and according to wikipedia, the 50 is a pineapple. Can't say I've ever heard that said aloud, but when all's said and done, you are never likely to confuse the denominations of our currency.

The greenback on the other hand - they are all small, all the same size, all green, all with the same layout, style, everything. So confusing! But they are green not black - now why is that?

Back in 1857 a chemist named Thomas Sterry Hunt invented the colour green that's used on the US bills. He used natural pigments and lab chemicals to come up with new colours and for this new green, he used chromium trioxide. Very cool idea, because back in the mid 19th century counterfeiters were really good at erasing the black numerals on paper money and then reprinting them with higher denomination numerals. What stood Hunt's new ink apart from the rest, back then, was that his ink was extremely difficult to erase, and because it wasn't black, but green, it wasn't able to be photographed. Now that is a clever invention huh? But that's not all... His ink is also practically indestructible; acid won't affect it and neither will most other chemical agents. Super ink!! Mr Hunt sold his ink invention to the US government and that green ink has been used since 1862 to print US bills. And that, my friends, is how US paper money became known all over the globe as the greenback.

Now, how much extra do I transfer for the 15 year old to finish her last couple of days in the Big Apple?

 I know she's bringing me some of these, so I'll transfer the cash!