Windows in Banknotes

Source: Giesecke & Devrient
Windows with various effects created using films or printing techniques are eye-catching, easily recognizable by the public, and can be checked for authenticity. Because each element is made up of a complex combination of different production steps, window elements represent an effective barrier against counterfeit attempts.To authenticate the window elements, users look at them directly, hold them up to the light, or view them at an angle against different backgrounds. All the devices use the same substrate – cotton banknote paper with a clearly defined opening that is sealed by a transparent laminated film.
varifeye_secureWindows_IMAGE_1COLThe varifeye see-through window allows you to clearly authenticate the banknote by comparing the appearance of the window against a light and dark background. The motifs of the design elements integrated in the window change their appearance depending on the background color.In the picture for example, several “V” characters can be seen in the window, but against a dark background the characters disappear and are replaced by the window in a book shape with a green and black hatched surface. varifeye is based on a complex manufacturing process and therefore offers a high level of protection against counterfeiting.
Varifeye Magic see-through window – conclusive authentication thanks to microstructure technology
varifeyeMagic_IMAGE_1COLThe varifeye Magic see-through window enables authentication based on microstructures. The tiniest microscopic structures become visible to the naked eye – hence the name”Magic”.At first glance, see-through windows based on this technology are transparent and only the individual shape of the window is identifiable. On closer inspection and when held up to the light, the magic effect allows the customer’s individual motifs to be seen and verified.Varifeye Magic is usually incorporated into a holographic foil so that the additional hologram effects provide support for visual authentication. The varifeye Magic see-through window is easy for the observer to recognize and is therefore ideal as a security element for rapid authentication. varifeye Magic was first used in the Kazakhstani 1000 tenge note in spring 2010.The complex manufacturing process for customized microstructures with moire; magnifier effects, combined with a holographic foil represents a particularly difficult obstacle for counterfeiters to overcome.
Making counterfeits easy to see through: the transparent TWIN see-through window (Transparent secure WINdow technology). TWIN-based features are easy to recognize and yet hard to imitate.
TWIN match
The information in the see-through window changes when viewed directly or at an angle. The effect is created by extremely accurate positioning of the front and reverse in relation to each other.
 twin_funktion01_IMAGE_1COL  twin_funktion02_IMAGE_1COL
 TWIN in direct light  TWIN held against the light
TWIN step
When held against a light background, an integrated printed graphical image can be seen in the window; when held against a dark background, a second piece of information is shown.
TWIN look
The functionality of optically variable inks, characterized by color-shifting as they are tilted, is enhanced with a different appearance when viewed directly or held up to the light.