engleski

Security printing innovation

Security printing, is constantly demanding continuing innovations in order to introduce adequate additional value to print-media “products” in the fight against forgery. In this paper we introduce the innovations that are result of intensive - advanced research on security printing elements, also referred as security graphics and s concerning the implementation on printed matters, documents and packaging. Security printing elements - graphics include various elements, such as individualised vector line graphics, rosette, guilloche, linear and hidden typography and as well individualised raster elements. These elements, are dedicated for design and production in various different printing and finishing processes applied as per example: intaglio print, offset, folio print, digital print, screen printing, hot stamping, etc. A common procedure in security printing is the application of hidden information, realized through the so-called “hidden” typography, vector graphics and pixel graphics in extended spectrum, from visual (400-700 nm) to near infrared spectrum (700-1000 nm). In particular, security printing elements are designed for usage in several spectral areas from UV (254 nm, 365 nm), through visual (400-700 nm) up to near infrared spectral area (700-1000 nm). Hidden security typography is implemented into the individualised raster graphics and inside the raster element itself. Design of the double graphics in the shape of individualised raster is the result of the long years of development and innovation in the field of security graphics and design of individualised raster elements. One of the most prominent innovation is Infraredesign, which, in principle enables the incorporation of a hidden picture appearing only in near infrared spectrum, in the four colour printing process and inks. Typography in the Infraredesign process is projected as hidden message through the programmed designer’s composition or structure. It is realised also through the twin dyes in various examples. Hidden typography in security Infraredesign graphics can be implemented in pixel graphics, hidden typography in linear vector graphics, hidden typography as programmed dot structure, coded typography or typography as part of the raster and a rasterization process. Among the various applications of Infraredesign is the one of “Dual - Twin” colours , which comprises the pairing of process and spot dyes - inks. Twins of colours which are investigated for every printing technique, dye type and substrates, are the basis for realisation of hidden information in near infrared spectrum by the Infraredesign method. Further, we discuss new spot twins dyes and their simulation with process set of dyes. In this sense, we propose the pallette of twin dyes for various dyes, materials and printing techniques. In the paper we concentrate in the use the results of experimental work of establishing the twin colours in their double V-NIR form. Double “dual - twin” graphics are a multilevel solution which is confirmed and detected in NIR spectrum with the sophisticated forensically device like Projectina. The prescriptions of the twin dyes are prepared in various printing techniques. Furthermore, we 59 present the algorithm of connection or nesting of the two or more various graphic samples which do manifest themselves differently in visual and near infrared spectrum. Each of the graphics has a separate domain for its appearance in a defined - specified light spectrum. This solution is the basis for the new printing technique as no mode exists in which by selective filtration in extended light area return to the starting state of creation of graphic samples is possible. In the plan of the dyes the dualism of the spot dyes is introduced. The same spot dye is created by the two or three various chemical prescriptions in order to reach different manifestation out of the visual spectrum. Research conducted revealed that with the twin colours, can provide a solid colouring and hidden image application for security printing, via the advanced combination of various elements - graphics in pairs of dyes-inks. Security linear graphics are realized in the rosettes, guilloche and Bezier’s curves made in loops, in order to include infrared component by thin lines which do overlap at various levels. Security linear graphics are created with sophisticated program solutions and realized with twin dyes cannot be copied without knowledge of all established parameters. Reproduction by photocopying is impossible because the copy loses its continuity and appearance of the image in in the extended spectral V-NIR area. Inside the infrared vector graphics linear typography is programmed.

Security printing, security printing elements-graphics, Infraredesign, colour twins, individualised security graphic

nije evidentirano