Registered Threads – Perfect Security, Perfect Storytelling

In the Banknote of the Month feature in last month’s Currency News™, we covered the Central Bank of Honduras’ new 200 lempira note which, among other features, is the first in the world to incorporate a registered Galaxy® thread. In this article, Louisenthal explains the significance of this new advance in thread technology.

The drive for ‘people-friendly’, easy-to-authenticate, complex security in banknotes is a continuous journey. Substrate embedded security is evolving, and even the fundamental recognised watermarks have a range of special tonal and highlighted properties.

The key for public authentication is an unambiguous and unique appearance of a banknote, using a registered platform. And significantly, we are seeing greater interest from issuers in these platforms. Nowadays, almost every foil on a new denomination is designed and applied in register. The thread has also developed significantly, and now the registered thread has elevated the security bar.

An unregistered security thread can be optimised with state-of-the-art precision registration. A registered thread with different and precisely positioned windows gives room for colourful storytelling in the banknote, and an easy reference for the public. The Honduras 200 banknote featured last month illustrates this dimension.

The registered thread can be optimised on Louisenthal´s RollingStar®, RollingStar® i+ and Galaxy threads, which utilise the proven micromirror technology, incorporating several million optimally-angled micro-mirrors per square centimetre. The combination of vibrant optical effects of ColourShift, exceptional dynamic movement and remarkable 3D come to life.

But why has this taken so long to develop?

One reason could be that the registered embedding of security threads is based on a different technology than the registered application of security foils.

Whereas the foils are applied on web or sheet application machines after finishing the paper, threads need to be registered during the process of sheet formulation in the paper machine.

By contrast, each thread needs to be placed exactly in the running direction, while being fed under the cylinder mould of the paper machine. A control system is essential to continuously check the position of the thread with the position of the paper (eg. by monitoring the watermark). And finally, an optical inspection system needs to double check the quality of this.

This technology was first implemented in 2017 on a house note by STC printworks in the Czech Republic, and now Honduras has taken the opportunity to integrate this advanced security technology into today´s banknotes.

What are the benefits in detail? Full design integration of the optically variable features:

• Cleartext is put where it belongs – under the paper bridges.

• Unambiguous authentication: each banknote thread looks exactly the same, the user recognises each window feature for dynamic authentication.

• Inherent protection against harvesting attacks: only those areas can show the effect, which are exposed in the windows.

And of course this can incorporate the enhanced magnetic readability: magnetic areas are positioned for sensor reading.

We anticipate this innovation will be featured in other impressive and memorable banknotes.