Telling the story of Bulgaria
The Bulgarian banknotes that have been in circulation since the late 1990s and early 2000s tell the fascinating story of Bulgaria through the centuries. They honour several personalities – from religious to artistic and from literary to philosophical. This was one reason why the BNB decided against a complete redesign when it kicked off an initiative to renew its notes in 2018.

However, one aspect was singled out for a major upgrade: security. The team of experts from the BNB, OFAD and Louisenthal sat down together to draw up requirements for each denomination in the new series. The partnership approach worked extremely well in this initiative, with each of the actors excelling in their particular field while taking into account the input and recommendations from the other partners.

It’s important and rewarding for central banks to keep banknotes both: secure and attractive.

Clemens Berger, Chairman of the Management Board of Louisenthal

Highly secure 100-lev note featuring Aleko Konstantinov
The first denomination to appear in the new series was the 100-lev note which has been in circulation as legal tender in Bulgaria since 28 December 2018. It portrays Aleko Konstantinov (1863-1897), a Bulgarian writer, publicist, lawyer, translator, democrat, and social activist. Konstantinov is best known for the book Bay Ganyo (Uncle Ganyo) in which he explores – not without humour – complex topical issues of his time, such as the road Bulgaria should take, its place in the world, and the culture shock between traditional ways of life and the customs and the culture of other countries. His works have been translated into nearly 30 languages.

As a prominent social figure, Aleko Konstantinov is credited with the idea of creating tourism in Bulgaria by climbing Cherni Vrah, at 2290m one of the country’s highest mountains. A copy of the invitation to this significant event is featured on the front of the new 100-lev banknote, along with an edelweiss flower as a symbol of the mountain, purity, and the indomitable human spirit striving for higher achievements. The flower subsequently became the emblem of the Bulgarian Tourist Union. The front of the banknote also depicts elements associated with the tourist industry in Bulgaria, as well as the title page of Konstantinov’s travel book ‘To Chicago and Back’. He is also celebrated on the reverse side of the banknote with several elements from his life and works. The note also shows a chessboard effect within the security features – perhaps a reference to the game of chess in which Bulgaria has a particularly strong international standing.

Security features on the 100-lev banknote

The 100-lev note showcases multiple state-of-the-art security features that are woven into the overall design and help users in Bulgaria easily and quickly verify the note’s authenticity.

The front of the note shows a dynamic RollingStar® LEAD stripe with a dynamic chessboard effect. The colour of the squares changes from emerald green to sapphire blue when the banknote is tilted. This RollingStar LEAD stripe synchronises with the three-dimensional image of the note’s value, 100.

The back of the note features a RollingStar® security thread with the same dynamic, colour-shifting chessboard effect. The micro text “BNB 100” is visible on both sides.

The note also contains security fibres embedded into the paper – a complex procedure carried out with exclusive machines, making it very hard to counterfeit. The fibres – in white, green and red – are barely visible to the naked eye but easily detected in automated processing using UV light.

A three-dimensional watermark portrait of Aleko Konstantinov, combined with the highlighted inscription BNB, is visible on both sides of the note in transmission view.

Recurring security feature designs are difficult for forgers to reproduce, which is why the team of experts from the BNB, OFAD and Louisenthal chose to echo the portrait of Konstantinov across the intaglio print, the watermark and the RollingStar LEAD stripe. The repetition of motifs also makes it easy for the untrained consumer to verify the authenticity of the banknote.

The banknote is also equipped with tactile features developed by Oberthur Fiduciaire for the visually impaired, with five thick and six thin diagonal lines along the margins on the front side.

The paper-embedded security features – the thread, the foil and the watermark – were supplied by Louisenthal.

New 100-lev note wins HSP award for cutting-edge security
The ingenious way in which robust security features have been woven in to the overall banknote’s design was held up as an example to follow at the High Security Printing EMEA conference in Malta in March 2019. It won the award for the Best Regional Banknote, with the judges recognising its “brilliant, beautiful and dynamic security features which correspond perfectly with each other and encourage the public to authenticate the note at first sight.” The award in general is given for “outstanding achievements in the design, technical sophistication and security of a banknote or banknote series”. For Clemens Berger, Chairman of the Board of Louisenthal, the award for the 100 Levs shows “how important and rewarding it is for central banks to keep banknotes both secure and attractive. We are honoured that the Bulgarian National Bank has chosen us to equip their new series with best-in-class paper-embedded security features. The use of our RollingStar LEAD stripe with its brilliant colour shift from emerald green to sapphire blue and the repetition of the main motif throughout the note strongly increase not only the attractiveness of the 100-lev note but also its security.”

Further denominations appearing during 2019
The BNB is continuing to release further top-security banknotes in 2019 and beyond. The second one to appear is the 50-lev note, which has been in circulation since November 2019.

Further Reading

Our three-dimensional, highlight and pixel watermarks can be used singly or combined – and we’re always working on new, advanced technologies that allow for a creative design. That results in higher protection and faster verification for everyone.



Embedded Covert Security
Louisenthal’s innovative, covert security features can be integrated in security threads to boost a banknote’s functionality at different authentication levels.



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.