Guardian™ at the Forefront of Banknote Security

As more central banks adopt Guardian™ polymer banknotes, CCL Secure redefines banknote security. 

CCL Secure was born out of a central bank’s vision to build a better banknote – one that was cleaner, safer and stronger – and this goal has underpinned Guardian™ polymer substrate technology ever since. Following several years of extensive research and development, Australia began the transition to Guardian™ polymer in 1988 with the release of the $10 bicentennial commemorative banknote. Polymer and the clear window had begun their journey into history.

Since then, the innovative Guardian™ banknote substrate has been used to issue in excess of 55 billion banknotes, gaining the confidence of more than 40 central banks for use in over 160 mainstream and commemorative notes that circulate in some of the world’s most demanding cash cycles.

Our polymer technology continues to evolve at an incredible rate. The development of new security features and designs are key drivers of this change. They inspire banknote designers to focus on the synchronisation of polymer and associated security features. However, all the complex elements that ultimately represent and protect the identity of a nation’s currency must be adapted to the printing systems. The aim is not to design a complex banknote that is difficult to produce, it is to design one that is difficult to counterfeit.

A window into the future of banknote security

When the first polymer banknote was launched in Australia in 1988, the presence of a clear window represented a new paradigm in security. It was a revolutionary new base material that, when combined with unique security features, instantly prevented casual and semi-professional counterfeiters from reproducing the notes. The film effectively combated photocopying. The clear polymer window has been so successful in deterring counterfeits that it has even inspired the creation of window features on a number of paper substrates. Today, the window remains a key security feature on polymer banknotes. It is highly secure and easily recognisable by the public.

Polymer substrate now has 30 years’ proven market performance, and Guardian™ has been at the forefront of polymer development throughout this period. The unique bi-axially oriented polypropylene (BOPP) Clarity™C gives Guardian™ its distinctive balanced tensile properties. These are not only exclusive to the polymer banknote market; they also provide superior printing and handling properties across all banknote-printing platforms.

Clarity™C film – in combination with CCL Secure’s opacification process, which includes printing and embedding security features on the film, creates Guardian™ substrate. 

Guardian™ substrate in combination with security features

£5 BanknoteThe Guardian™ platform allows CCL Secure to include not only a wide range of proprietary features but also third-party features, such as optically variable inks (OVI) and optical variable devices (OVD) applied in windows. These can be integrated within our Clarity™C base film or applied directly onto Guardian™ substrate.

The multiple opacification layers that make up Guardian™ allow CCL Secure’s proprietary features to be applied at various stages of manufacture: within a clear window, under one or multiple layers of opacification, on top of opacification, or a combination of all three. This increases feature integration, complexity and security.

Examples of features that can be applied in a clear window and viewed from both sides of the substrate are:

  • CAMEO™: a rich, tonal image printed within the transparent window
  • LATITUDE™: an optically variable device providing colour shifts and movement within the image when tilted, with the added security of being see-through in transmission
  • ECLIPSE™: an optically variable device that reveals a hidden message when looking through the transparent window at a point light source
  • AURORA™: a combination of two OVIs that match in reflection but are different in transmission.

Other features, such as Shadow Image™, Shadow Image Thread™, Micro Lettered Thread™ and MAGread™, can be applied under one or multiple levels of opacification, allowing designers to hide them beneath banknote printed features, or create tonal effects with different layers.

METALIX™, IRIswitch™ and Spot Colour™ are printed on the surface opacification layers for a more obvious effect. Opacification layers also allow features such as AURORA™ and GSwitch™ to be printed in a Half Window™, creating a switching effect on the window side and a tinted substrate on the reverse.

The combination of layers means the design possibilities for Guardian™ are limitless. A banknote designer can allow their imagination to transcend multiple layers, rather than being restricted by the flat surface of a paper substrate.

What are the drivers to switch from paper to Guardian™ polymer?

Security is just one of the many benefits of Guardian™. There are a number of drivers behind a central bank’s decision to switch a single denomination or a full series to Guardian™. These include:

  • Increased security – The use of the Clarity™C film, combined with clear windows and the integration of Guardian™ features, reduces counterfeit rates by a factor of ten when compared to existing paper banknotes.
  • Cost savings – Cost savings arise mainly from the increased lifespan of the banknote, which is typically three to five times that of paper banknotes. Improved lifespan also has a knock-on effect on cash cycle savings, with a reduction in the movement of banknotes, sorting and handling playing a significant role.
  • Reduced environmental impact – By adopting a 100% recyclable Guardian™ product, central banks not only reduce their impact on their local environment, they also save costs by selling used polymer for recycling rather than sending it to landfill.
  • Improved hygiene – Independent studies have shown that Guardian™ contains significantly less bacteria than paper banknotes, which can help reduce the spread of disease.
  • Customer perception – A full Guardian™ series adds consistency and reduces confusion for the general public, especially in the areas of touch and feel. The suite of Guardian™ features allows for a coherent theme throughout a series, allowing for faster identification.
  • Cash handling – A full Guardian™ series creates less complexity at cash processing machines, and gives central banks better purchasing power by providing a cleaner note handling experience for the public.

While paper is a flat two-dimensional structure, polymer substrate is effectively a three-dimensional space. As CCL Secure’s R&D scientists work from the microscopic to the nano-level, this space is getting larger and larger. These spatial characteristics are the key reason that Guardian™ will continue to stay ahead of counterfeit technology far into the future.


CCL Secure will be participating at the Anti-Counterfeit & Currency Expo and Conference, taking place November 6-8, 2018 in Las Vegas, NV. 

To hear more about their products and services, register online for your free delegate pass.