Denis Jurečić

Security Methods in the Art and Science using Spectroscopy in the Visual and Near Infrared Range

Near infrared Z values are determined with spectroscopy of colorants, which are used in security charts, printing of documents and banknotes. A new application of security methods in informatics is being observed in this article. The processes of dyeing of fabrics are being controlled by programming twin dyes. Two different mixtures of dyes have been created for the same color. They differ in light absorption only in NIR area. The given, desired difference in their values of light absorption and NIR spectrum has been achieved. Conversely, those are two dyes of different mixture but with the same color parameters in the visual spectrum. The dyes have identical spectra graphs of light absorption in the visual area. The experimental result has been shown in the gallery with infrared pictures and through the design of textile clothes that carries the hidden information. The design with text ―IJNTR – VZ security‖ has been analyzed by forensic light blockages from 400 up to 1000 nm.

SIGURNOSNA ETIKETA SOKA OD ARONIJE SKANIRANA UBLOKADAMA U BLISKOM INFRACRVENOM SPEKTRU

We have developed new procedures in order to secure family agricultural production (FAPOPG). As organic aronia juice has considerably high prices and a big competition, we have applied Infrared Design® (IRD) protection on the juice label which is liable to forgery. The developed CMYKIR color separation for two different spectra widens the application of graphic protection for various products through all printing techniques and technologies. Visible and infrared colors are being prepared according to the new and hereby suggested recipes. The new graphic protection, which has the information about product, manufacturer and designer, has been secured thus protecting the final consumer. The separated NIR (near infrared) information has been created, which is detected in NIR area of wave length from 750 to 1000 nm. Designer determines the procedure of the process IRD through the individualized choice of colors as well as the forming of the visual near infrared image. The suggested forensic solution of the aronia juice label is scanned in blockades of two light areas as multilayer specimen which contains hidden and

Spectroscopy of Colorants for Fine Art in Visual and Near Infrared Spectrum

We are studying inks through information of their absorption spectra. Data are measured continuously in visual and near infrared region. New color hues are achieved by different colors mixtures, but their appearance properties are respected in both spectral domains. Measured spectra of dyes are key information for identification of twins, for at least two dyes, that obtain equal spectrograms in visual, but different in near infrared region. New colors are prepared for ceramic application with “metallic-gold” ink This article presents light colors in the visual spectrum, and which have high absorption values in near infrared spectrum. Dyes with the addition of metallic gold, significantly changes the direction of research on the development of the twin colors and dyes.