A Trip Through Holographic Threads and Stripes

The recent HSP (High Security Printing™) Latin America conference in Nassau, the Bahamas gave holographic foil manufacturer Hueck Folien the perfect platform to showcase its portfolio of stripes and threads for banknotes.

Hueck Folien is a family-owned business, founded in 1970, which now employs 300 staff and exports to over 65 countries from its manufacturing base in Austria.

The company has an enviable sustainability record and plans to have ecologically neutral production by 2035 with film from recycled materials. It is also constructing a 400kW photovoltaic plant which is predicted to save greater than 100 tonnes of CO2 per year.

During the presentation at HSP LatAm, Jan Hofmann, Head of Security Sales, set out the company’s references for holographic features on banknotes which include the euro, Swiss franc and full series in Brazil and Sweden.

Reviewing the Swiss franc Series 9 gave Jan the opportunity to go into some details about the company’s transfer security thread, which was a special development with the Durasafe® substrate from Landqart. Durasafe is a composite of paper and polymer, two outer layers of security paper are fused together with a central core of transparent polymer. Being a transfer, rather then applied, product means that the security thread is roughly half the thickness of a regular thread and doesn’t suffer from ‘wobble’ inside the paper, resulting in precise positioning inside the window.

Jan then went on to describe a product development - TRILUMIC®– which is a trademark resulting from cooperation between Hueck Folien and Banque de France.

The National Bank of Cambodia was the first central bank to put the TRILUMIC® stripe on its 15,000 riel commemorative banknote in 2019. For a commemorative banknote the volumes were high, partly because the banknote is officially legal tender and is circulating in the country.

The stripe was integrated in the banknote concept and applied on Durasafe. The uniqueness of TRILUMIC on a holographic stripe is that it is possible to print a full colour halftone image in high resolution and registration.

More recently, the National Bank of Cambodia launched the second banknote with a 15 mm TRILUMIC stripe, the commemorative 30,000 riel, now also in circulation.

A new dimension in holographic threads

According to Jan’s presentation, using the TRILUMIC technology for banknote threads opens up completely new options for the banknote designer. The feature can be applied to all kinds of thread types and widths. TRILUMIC adds a particularly attractive function to different technologies including printed and metallised threads.

What makes the TRILUMIC feature different to other UV-designs on banknote threads is that, as opposed to spot or rainbow colours, TRILUMIC allows you to create very precise and customised designs in text, motifs and colour overlapping, enabling the creation of very bright UV white and negative text in UV.

Jan went on to say that TRILUMIC creates completely new designs for banknote threads. For instance, if the designer plays with the demetallised area of the thread, very distinctive image elements can be generated by switching on the UV light when suddenly a much wider thread in brilliant UV illuminates. Invisible in daylight, extremely brilliant true-colour halftone images appear under UV light.

Reef Stripe

The latest sample of high security foil stripe presented by Jan, created specifically for the HSP event, was inspired by the underwater world – appropriately given the location - with its luminous colours of reefs and the silver reflection of light under water. The samples shown by Jan demonstrated improved print for TRILUMIC with strong brightness of the colours.

The hologram appears to be in prefect registration to the UV-print, as best as the eye could tell, and the fiery colours of the hologram are in stark contrast to the white rendered effects. There are also colour-relief structures with 3D effects of the coral.

In conclusion to the presentation, Jan made a strong case that threads and foils on banknotes are features that the public really enjoy engaging with. And anything that makes the public pick up and play with the surface of a banknote has got to be good for counterfeit detection!

Reef stripe (© Hueck Folien).