Australian banknotes are printed on polymer, a type of plastic, and they have a distinctive feel. Polymer banknotes were developed to make our currency more difficult to counterfeit. The polymer makes it possible to include a range of security features on our banknotes.
The security features that can be used to check a banknote are:
The plastic that Australian banknotes are printed on gives them a distinctive feel. A suspect banknote may feel thicker or thinner and lighter than a genuine banknote. Most counterfeits are printed on paper and can be easily torn. It is difficult to start a tear along the edge of a genuine banknote. A genuine banknote should return back to shape after it is scrunched up.
The clear window should be an integral part of the banknote and not an addition. Check that the white image printed on the window cannot be easily rubbed off. Also look for the embossing – there is a wave pattern in the window of the $10 banknote, and the value of the banknote in the windows of $20, $50 and $100 banknotes. There is no embossing in the window of the $5 banknote.
See-through Registration Device
Diamond-shaped patterns are printed inside a circle on both sides of a banknote. When a genuine banknote is held up to the light, the patterns should line up perfectly to form a seven-pointed star within the circle.
When a genuine banknote is held up to the light, the Australian Coat of Arms should be visible under the print. This ‘shadow image’ is created by variations in the background printing on the plastic substrate.
Intaglio is raised dark printing with a distinct feel. On genuine Australian banknotes, the slightly raised print can be felt by running a finger across the portraits and other major design elements.
Background Print (offset)
Multi-coloured and multi-directional fine-line patterns appear on each side of the banknote. This background printing should be very sharp. Check for irregularities such as less clearly defined patterns, thicker or thinner lines, or colour differences.
Tiny, clearly defined words are printed in the top left corner of the $5 banknote, and near the portraits on the other denominations. Most people need the help of a magnifying glass to read the microprinting. Most banknotes have their denomination microprinted in words (e.g. ‘FIFTY DOLLARS’), but the $10 banknote has poems by AB ‘Banjo’ Paterson and Dame Mary Gilmore microprinted on it.
The serial numbers of an Australian banknote should fluoresce under ultraviolet light. Also, a rectangular patch showing the value becomes visible on the $20, $50 and $100 banknotes, and a square patch appears on the $5 banknote.
To validate the UV fluorescent features on Australia's banknotes, it is recommended that a UV black light with a wavelength that is centred around 365nm be used, and that it is done so in low ambient lighting conditions. Many UV black lights that use Light Emitting Diodes (LEDs) emit wavelengths between 395 – 400nm, which are not suitable for viewing the UV features.