GUARDIAN™ is underpinned by a specialty polymer film called Propanote™ Clarity C. It was developed by our sister company Innovia Films, to provide an optimised platform for CCL Secure’s process of printing opacified layers of polymer substrate embedded with security features.
Clarity C is a biaxially oriented polypropylene (BOPP) film with a unique and proprietary production process involving a ‘bubble’ that is four storeys high. It is reserved for exclusive use with GUARDIAN substrate.
Clarity C is one of just two bank-grade films in the world. The other is Propanote™ Opacity W, which is used to create SPARTAN™ banknotes. The most obvious difference between the two films is that whereas Opacity W is fully opaque, Clarity C is completely transparent. This supports the inclusion of large, complex windows.
The production process begins with clear pellets of polymer, which are fed into the top of the ‘bubble’ and melted. As the liquified polymer flows down the ‘bubble’ it is stretched into a delicate but highly durable material manufactured to a thickness that is ideal for banknotes. Its balanced tensile properties are produced through the effects of gravity outside the bubble, and air pressure inside.
An important aspect of this proprietary process is that it imparts a unique security signature into the film. This can be detected via machine inspection at speed, to support central banks in combating counterfeits.
By the time the polymer reaches the base of the ‘bubble’, it has been transformed into a solid film. This is then rolled onto reels nine kilometres long, and delivered to CCL Secure in Australia, Mexico or the UK.
Once the reels of Clarity C have been delivered, CCL Secure prints opacified layers onto the film. Each layer offers an opportunity to enhance banknote design at the same time as embedding advanced security features directly into the polymer core.
The print layering process means security features can be applied at various stages of manufacture – within a clear window, above or below opacified layers, or a combination of all three. This complex integration of security features is one of the key reasons GUARDIAN banknotes are more secure.
Cotton-paper banknotes are produced using a different process. Most security features are applied on top of the substrate, which means designers are effectively working in a flat, two-dimensional space. In contrast, CCL Secure’s research and development scientists work in a layered, three-dimensional space at the micro to nano scale, which is why GUARDIAN banknotes are so effective at reducing counterfeit rates.