That breakthrough was the creation of bi-axial polypropylene (BOPP) in the mid-80s, a transparent polymer base material that possessed the properties needed for banknote security to move from the existing two-dimensional platform of traditional cotton-paper banknotes to a revolutionary three-dimensional platform using opacified substrate layers.

From the outset, the large transparent window that BOPP enabled became the hallmark of Guardian^® banknotes. From its launch with the Australian commemorative $10 in 1988 until this day, the entire Australian banknote series continues to use WinTHRU^® transparent windows integrated with WinVU^® vignettes as its main security feature, such has been the effectiveness of this security combination in addressing the threat of counterfeiting in Australia.

Research into additional security features throughout the 90s continued, and in 2000 New Zealand released its banknote series using WinBOSS^®, an embossed transitory image in a transparent window. Mexico also chose WinBOSS^® in their 20 Peso note two years later.

It was apparent by this time that Guardian^® banknote substrate was an outstanding platform for advanced security features because of its ability to accommodate a range of technologies at one time: multi-coloured layers, graded opacity, high tech inks, laser technology and optically variable devices, diffracted light devices, and most recently nanotechnology.

Throughout the last decade, the over-riding development theme of Guardian^® banknote substrate has been ‘synergetic integrated design’, that is, security features that through their integration enhance both complexity and design. This is vividly seen through the evolution of transparent window complexity from the Australian $100 note (1995) comprising WinTHRU^® transparent window and WinVU^® vignettes to the Nicaraguan C200 note (2009) comprising WinTHRU^®, WinVU^®, Gold METALIX^™, G-Switch^® and a shadow image (used to build the picture of the dancer).

As the demand for banknotes increases around the world, so does the growth of counterfeit operations who will use any and all available technology to perpetrate their crime. It is therefore critical that the banknote industry stay ahead of counterfeit operations.

As the leader in banknote counterfeit prevention, Securency will maintain its innovative approach to researching how it can best use security technology in the numerous layers of substrate that comprise Guardian^® banknotes.

One of the underlying strengths in the Design Evolution of Guardian^® banknote substrate is its ability to utilise all security printing processes including offset, screen printing, foil application, intaglio, letterpress and over-coating processes. The effectiveness of some of these processes is even enhanced using Guardian^® due to the synergy offered by the smooth surface and the transparent windows.

Securency’s ongoing commitment to leading edge banknote security requires it to remain at the forefront of technology, and the firm’s R&D program continues to further enhance the security features used in Guardian^® banknote substrate, and to develop new security features. This approach ensures that Securency’s clients will always have access to the broadest choice of banknote security options available in the market today and in the future.