G+D Magazine
3D visualization of different fields with zeros and ones

Unique security features inspire greater confidence in banknotes

Nowhere is confidence in a product more important than with banknotes. Security features are intended to put a stop to illegal copying by helping to distinguish real banknotes from counterfeits. Along with watermarks, which have been part of banknotes for over 350 years, security threads are the most important security feature and also the easiest for people to recognize.

The arrival of scanners and color printers in day-to-day life in the nineties posed new challenges for banknote printing companies and manufacturers of banknote paper. As a result, they developed their security features even further. The embedded metallic threads used in the early days were only the beginning. Nowadays, developers primarily rely on optical effects such as changing colors or images. Holograms and color-shifting effects in the form of threads, stripes, or patches now protect many different banknotes and pose an ongoing hurdle to counterfeiting attempts. Security features have to be counterfeit-proof and, at the same time, clearly identifiable beyond any doubt. That is why it is so important for security features to incorporate eye-catching color and movement effects to attract the attention of the user.

Security at first glance

With RollingStar®, G+D subsidiary Louisenthal has developed a thread that meets these requirements and sets new benchmarks with its visual effects. Vivid, striking, and absolutely stunning, the RollingStar® makes security even more attractive by combining movement with changing colors for the first time. This completely new effect is incredibly eye-catching and ideally suited for immediate authentication. A good example of the effect in use is the "Rolling Bar", in which a dynamic reflection of changing colors moves over the surface of the thread and a striking color shift takes place.

Close-up of a Rollingstar security thread on a specimen banknote

Pioneering technology leaves counterfeiters behind

New effect: dynamic ColourShift reflection

RollingStar®’s many optical and functional features are only possible thanks to the combination of micromirror technology and color change effects. As the name suggests, the mirrors in question are extremely small and reflect light. Typically, a mirror reflects white light, rather than splitting up the individual colors. Unlike most everyday mirrors, however, the RollingStar® mirrors are not made of glass but are embossed

Close-up of tiny reflective facets on the surface of banknotes

An area of 1 cm² holds several million facets.

Each of these tiny mirrors is positioned at a specific angle calculated precisely beforehand by special software designed for this purpose. The movement effect is created by the exact alignment of the vast number of reflective facets. When light hits the surface, its reflection moves across the note when it is tilted. Here, too, the reflection is initially white. Only in combination with multi-layered vapor deposition is an additional, exactly defined color change generated by tilting the note. Even the smallest deviations in the layer thicknesses would lead to a different color appearance.

United we are strong: RollingStar® and SICPA SPARK ®

Synchronization of the RollingStar® effect with optically variable printing processes (such as OVMI SICPA SPARK ®) opens up additional security potential. Two completely distinct security features are thus synchronized and used in tandem. This makes it even easier for the public to identify genuine notes. Furthermore, synchronizing two high-tech security features from different production stages – paper manufacturing and banknote printing – increases protection against counterfeiting.

The 200 Zloty is the first banknote with RollingStar® in Europe

A 200 zloty banknote with Rollingstar security thread

The Central Bank of Poland issued the new 200 Zloty banknote in February 2016. It is currently the highest denomination in the series, which has been updated since 2014. In 2017 the 500 Zloty will follow as second banknote equipped with RollingStar®. Interview with the expert Mr. Grzegorz Biernat of the Cash & Issue Department of the National Bank of Poland.

Mr. Biernat why did you choose RollingStar® security thread rather than other threads?

Grzegorz Biernat: Our first goal was to find a distinctive design with colour and dynamic effects that could be easily explained to the public, and well matched with the similar effects of a printed feature like SPARK ®®. Secondly, the thread should not be too thick, to avoid waving of paper. Thirdly, we looked for a thread with a reasonably high magnetic signal in order to guarantee machine readability during banknote processing.

Several designs of RollingStar are available. Why did you choose RollingStar Cube?

The RollingStar Cube effect shows the best similarity with SPARK ® design. When you tilt the note, the dynamic and colour shifting effects on both features, thread and SPARK ®, are perfectly matched and simplify authentication by the user.

Why did you choose RollingStar in combination with Sicpa SPARK ® for your highest denomination? Do you believe the similarity in effect helps the public authenticate the note?

It was our objective to make this denomination, which represents a substantial value, as secure as possible. The combination of two high level security features, which are produced in different production steps, is a perfect match of eye-catching effects. Yes, our goal was to achieve similarity as we believe it can be very helpful for public.

What was the reaction of the public when the design was presented in autumn 2015 for the first time?

Reaction was positive. In addition to the watermark, which is still the most recognised security feature, the public liked the idea of two striking features which are synchronised in movement and colour shift.

With regard to security features, what were the key characteristics the National Bank was seeking for the 200 Zloty note?

In order to ease authentication by the public, we were looking for dynamic, and at the same time, attractive, features.

Was there significant counterfeiting of any of the high denominations which led the Bank to raise banknote security level?

No, there was not. As a Central Bank, however, we always have to be one step ahead of the counterfeiter and this was the reason why we decided to upgrade the security level.

The series has been issued only in the last two years. Are there any further banknote requirements you anticipate in the coming years?

The last note in the series will be PLN 500. We plan to issue this denomination in 2017.

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