Spectral Pre-Compensation and Security Print Deterrent Authentication

Security printing and imaging is the application of printing to provide product authentication and brand protection through the use of difficult to reproduce (overt) effects and the addition of data (overt, steganographic, covert and forensic) to the printed elements. The density of data added to security deterrents can be improved through the process of pre-compensation. Structural pre-compensation involves altering the size and shape of a printing element so that after reading (printing and scanning) the element better matches its intended size and shape. In this paper, we address spectral pre-compensation, in which the colors of the color file, a 3D bar code, are changed before the printing and scanning take place. We show the increased security deterrent density possible using this approach using inkjet and dry electrophotographic printing technologies. We also show that the technology is generally applicable except in cases where there is a printing quality issue. Thus, spectral pre-compensation is shown to be generally applicable for testing print quality and increasing security deterrent density simultaneously.