Polymer Banknote - Development of Polymer Banknotes

Development of Polymer Banknotes

Polymer banknotes were developed to increase the security of Australia's paper currency against counterfeiting. In 1967 forgeries of the Australian $10 note were found in circulation and the RBA was concerned about an increase in counterfeiting with the release of colour photocopiers that year. In 1968 the RBA started collaborations with the CSIRO and funds were made available in 1969 for the experimental production of distinctive papers.

The insertion of an optically variable device (OVD) created from diffraction gratings in plastic as a security device inserted in banknotes was proposed in 1972. The first patent arising from the development of polymer banknotes was filed in 1973. In 1974 the technique of lamination was used to combine materials; the all-plastic laminate eventually chosen was a clear, BOPP laminate, in which OVDs could be inserted without needing to punch holes. The BOPP substrate is processed through the following steps:

• Opacifying - two layers of ink (usually white) are applied to each side of the note, except for an area(s) deliberately left clear for creating an OVD;
• Sheeting - the substrate is cut into sheets suitable for the printing press;
• Printing - traditional offset, intaglio and letterpress printing processes are used; and
• Overcoating - notes are coated with a protective varnish.

BOPP is a non-fibrous and non-porous polymer. Compared to paper banknotes, banknotes made using BOPP are more durable, harder to tear, more resistant to folding, more resistant to soil, waterproof (and washing machine proof), easier to machine process, and are shreddable and recyclable at the end of their lives.