Durasafe® is the world’s most advanced banknote substrate. A composite of paper and polymer, two outer layers of cotton banknote paper are fused together with a central core of transparent polymer. The paper layers are fully functional, and allow for the incorporation of well-known features such as watermarks, security fibres, threads, and other traditional security elements, including taggants. The cotton paper also ensures that the finished banknotes retain the special tactility and feel that is so characteristic of banknotes and immediately recognised by the public.
The polymer core can be used to form crystal-clear see through windows (called Thrusafe™) in any position on the banknote, creating a feature that is instantly recognisable, intuitive to verify, and easy to explain to the public. The window designs can also be used to complement the denomination: a different window design for each denomination eliminates the possibility of “uprating” a banknote from a low denomination to a higher one.
The multi-layer structure also makes it possible to have windows in just one of the paper layers (called Viewsafe™), something that can be used to highlight the watermark, or to create innovative shapes through which to see the security thread. In addition, the paper layers can be different colours (to best work with the design), and it is possible to use the Viewsafe™ windows to see into the centre of the banknote and view the colour of the other paper layer. The range of possibilities is as broad as one’s imagination.
In addition to the security and design options that Durasafe® offers, the composite structure creates a substrate with greatly increased mechanical strength: tear and fold resistance is substantially higher than standard paper, resulting in banknotes printed on Durasafe® being able to last longer in circulation. What’s more, that strength also impacts how it performs during printing. It is more stable than normal banknote paper, making it perfect for printing fine lines and retaining the tactility of intaglio print over time.
The combination of security and durability make Durasafe® very versatile. For denominations that move quickly through the cash cycle, typically lower or middle denominations used for everyday payments, the strength of Durasafe® is ideal. Where greater security is needed, windows can be used in combination with other security features to maximise resistance to counterfeiting, and the ease of educating the public on how to identify authentic banknotes.