Colour: turquoise, brown & black
Design: Flock of birds
** Roughly cut along bottom, very early trial of polymer note technology
About Polymer Banknote Trials
As a result of the appearance of paper $10 forgeries in 1966 the Reserve Bank of Australia collaborated with the CSIRO with experiments to find a new forgery-proof banknote. There were a number of trial notes produced by the CSIRO in the form of various denominations, but the project eventually concentrated on the production of polymer notes.
Experiments with the use of an optically variable device (OVD) on or within clear areas on the plastic were developed and many variations were produced as $50 notes.
Eventually the RBA purchased the technology from the CSIRO and produced the plastic Bicentenary $10 note for circulation in 1988.
Some of the CSIRO $50 notes and in one major case variations of the OVDs have ended up in the hands of the public and have been sold in auctions or via the internet.
Two variations of the $50 note have been seen that appear to have been printed from two different printing plates, bearing STU 789018 or ZZZ 000000 serial numbers.
Two main differences in the STU and ZZZ notes are captions for the (non-official) signatures and forked or non-forked tails on the birds.
STU notes had the legal tender clause “This Australian note is legal tender throughout Australia and its territories” and ZZZ notes “Legal tender throughout the Commonwealth of Australia and the territories of the Commonwealth”.