The second joint winner was the Printing Works of the Bulgarian National Bank (BNB) Corp, which produced its first ever house note to celebrate its 30th anniversary in 2024.
The intricately designed and highly complex note is broadly themed on butterflies and maths. The front features a portrait of Edward Lorenz – mathematician and meteorologist – who discovered chaos theory and whose description of the Butterfly Effect (the idea that small changes can have large consequences) provides the accompany visual graphics. The reverse continues this narrative with graphic elements of a butterfly in flight.
The production of the note involved dry and wet offset, intaglio and screen printing, with a diffractive stripe from Demax featuring 3D and bas relief effects, a , positive/ negative e-motion effect, an achromatic micro engraved portrait, micro- and nano-engineered images and registered demetallisation.