Australia has used plastic bank notes since 1988, when they were developed by David Solomon and colleagues at the University of Melbourne as an anti-counterfeit measure. Writing in Angewandte Chemie Solomon explains just how successful his invention has been over more than two decades of financial transactions. "Our idea was to develop materials that could not be photographed," explains Solomon, that notion eventually led to the use of clear plastic films as a substrate in place of paper. A banknote with a transparent window made of a plastic film is a simple but highly effective security feature. The material selected was a polyethylene/polypropylene/polyethylene film. Counterfeiting in Australia and other countries that have since adopted plastic bills, including Brazil, Romania, and New Zealand, has dropped by 90%.