Social media users went into a spin after a sleuth discovered that every Aussie banknote features a hidden image. But it’s not the only secret our notes have.
Reddit users went into a spin on Monday after a sleuth discovered that shining a UV light on Aussie banknotes revealed hidden images of birds.
Reddit user C_Horse21 made the discovery with a $100 note and shared it online, quickly racking up over 2400 “upvotes” and setting off a frenzy in the comments.
“Man, American banknotes are boring as f**k,” one user said, decrying the lack of National Treasure-styled secrets on the iconic US greenback.
“For all everyone had a go at the new $5 when it came out, our banknotes are actually pretty damned cool,” said another.
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Every Australian banknote includes three “invisible” features – a bird, serial number and year of print – created using fluorescent inks.
Each note has a different bird: the eastern spinebill honeyeater ($5), cockatoo ($10), kookaburra ($20), black swan ($50) and owl ($100).
While the hidden bird may have prompted a wave of conspiracy-like excitement, it’s actually one of several unique security measures built into the design of our notes to combat forgery.
Read on for a detailed list of what other Easter eggs are contained on the loose fiver sitting in your pocket, as well as how to spot a fake.
The feeling of the note itself
Perhaps the best way to spot a fake bill is by feeling the main number at the bottom of the note.
The slightly raised print can be felt by running a finger across the portraits and numerals.
Given all notes are made of polymer, a distinctive type of plastic, they should also spring back into place after being scrunched in your hand.
The polymer banknote, developed jointly by the Reserve Bank and CSIRO and introduced in 1988, was a world-first in the currency world and made it possible to install a range of protective features that made Australian bills the most secure in the world.
It’s now used by more than 50 countries including Russia, Canada and the UK, with updated designs regularly rolled out here in Australia.
The clear top-to-bottom window that runs up the center of any banknote is a trademark feature of Aussie hard currency.
However, the multiple images contained in the window aren’t just decorative – they’re to help you identify a dirty bill.
The star-shaped image at the top of the window should appear either raised or recessed when you tilt the note.
The same “tilt-test” can also be applied to the outlined flying birds in the window, which should appear to move their wings and change color when the note is moved.
The more detailed colorful bird included in the window should also change color when the note is angled.
A seven-pointed star in the bottom right window of the note should also be clearly visible when held up to the light.
The numbers (and colours) don’t lie
If any doubt about the validity of your cash still persists, try inspecting the small building at the bottom of the central window.
The denomination of the bill should be visible inside when the angled.
This number should mirror itself as the note is moved, appearing both forwards and backwards depending on how the note is tilted.
Another telltale sign of an authentic note is the “rolling color effect”, with a kaleidoscope of colors visible within the bird in the top left corner of the bill.
This “colour test” is also where the UV ink comes in, with the “secret” bird uncovered on Reddit visible on real notes when held under a UV black light with a wavelength centered around 365nm.
If you’re trying this at home and any of the above tests fail, you’d best hand in your note to local authorities as quickly as possible.