Durability dilemma? Unmatched security from within
Cotton banknotes are still now the substrate for 95% of the world´s banknotes and continue to be the basis for substrate-embedded innovation which has harnessed both security and durability. We know durability of cotton substrates has been a growing requirement of issuers seeking a more cost-effective solution, so these benefits are all now packaged in Hybrid ADDvance®.
Let´s briefly see how this innovation developed. Cotton banknotes already have high strength due to the cotton fibres, but this also attracts moisture and dirt through circulation. Significant improvements have been made by adding plastic fibres and special coatings. There are many references for this, but perhaps amongst the best known is the ECB, achieving over 50% lifetime increase through varnishing. However, there are other ways to increase lifetime in circulation.
The structure of a Hybrid composite substrate with security features.
High humidity will cause the notes to lose their stiffness and machining gets very difficult as a result. This can be prevented by applying a thin plastic film instead of the coating, to act like a raincoat, which provides a much greater resistance barrier to dirt and moisture. In this sense the note has similar durability properties to a polymer note, and this was the driver for Hybrid, originally developed to increase banknote lifetime particularly in challenging circulating conditions. But this cotton-based durability concept offers an even greater potential in terms of embedded security: optimal circulation durability for foil elements such as stripes and patches.
So we developed Hybrid ADDvance to ensure that the security elements could also be protected under this protective film, and thus be protected from wear and tear. The ultra-thin protective shield provides a soiling barrier for the banknote.
Therefore, the investment in the most secure and attractive features can now also be protected. And the multi-layered construction also optimises counterfeit resistance. No other substrate is able to offer such high feature durability as is achieved by Hybrid ADDvance.
How to protect the security
So while we apply foils to the substrate, Hybrid can also adopt secure windows either through apertures overlaid with foil or wide window threads. Thus, an unprinted transparent region is now a dynamic and secure solution which is sophisticated and can integrate with other printed and foil features. And with the security built in, it’s fully scalable for low and high denomination notes, enabling integrated patches with windows, Micromirror LEAD stripes and RollingStar® threads and definitive watermarks.
Substrate which performs and protects – how do we do it?
Advances in substrate is the key, and Hybrid ADDvance also provides a design platform for the higher denominations. It protects all security elements – watermarks, foil elements and patches, threads and security fibres.
The protective film is about 6 microns thick, but forms a major barrier against moisture and dirt. Then an ink receptive layer is applied in several layers. The structure is one of the technological keys of Hybrid ADDvance, which ensures that the foil elements that are embedded into the substrate retain their brilliance and do not become cloudy due to the layers above.
This is the finished substrate, which is then printed like a normal banknote. Subsequently it is varnished to protect the banknote print and prevent colour abrasion.
How long do Hybrid notes circulate compared to cotton notes? The general result is a circulation time around three times longer than that of pure cotton notes, depending on the denomination. This finding was proven in a dedicated machine-based observation of the cash cycle in Jamaica.
In the development phase of new products, one has to rely on laboratory methods to verify the success of the development. Extreme tests are usually conducted to efficiently prove the robustness of the substrate. An essential aspect is the simulation of wear by the human hand. The slow wear that takes place in circulation is simulated in the laboratory by synthetic sweat and mechanical-chemical stress.
In developing Hybrid ADDvance, the key goal was to integrate high-quality security foils in such a way that they retain their optical brilliance until the end of the banknote's life, and can thus be authenticated. The fine structures are usually damaged early when exposed to unusually high stresses, especially through perspiration and mechanical strain, and so far this problem has not been solved for many central banks. For the laboratory test, a cotton note with LEAD serves as a reference. If the note is soaked with synthetic sweat (Iso Norm), the strip is rapidly attacked from both sides, the metal layer corrodes and decomposes very quickly under these extreme conditions. In contrast, the fully embedded foil element in Hybrid ADDvance remained completely intact for several weeks.
Hybrid ADDvance housenote series – the pictures tell the story
Our new Hybrid ADDvance housenote series depicts the idea of a protective cover that later reveals something unexpected and colourful. Each of the notes has its own story and security feature, and we have also developed an app which presents the notes in a very engaging and intuitive way.
The 10 MicroMirror LEAD note – which recently won the IHMA Award for Best Applied Security Product – is the result of a combination of micromirror and hologram technology, whilst the 20 combines micromirrors with holograms and RolllingStar thread.
Hybrid ADDvance® and Hybrid™
Hybrid ADDvance and Hybrid are Louisenthal’s solutions for durable and highly secure banknotes from low to high denominations.
RollingStar® Security Threads
RollingStar’s striking colour shift and dynamic effects are a real eye-catcher and ideal for immediate level-one authentication. Use them to achieve distinctive effects, such as the striking “rolling cube” where a truly dynamic colour shift reflection travels over the surface.
LEAD / Micromirror and Holographic Foils
Our micromirror foil technology offers top quality with its shining metallic surface. It offers a stunning display of shifting patterns, making verification easy. The foils combine cutting-edge micromirror and hologram technologies.