Security printing is the use of variable data printing (VDP) to add readable information to printed regions. This is used for brand identification, track and trace, product authentication and if applicable for investigation and evidentiary purposes. Wellcrafted, multi-region deterrents can be powerful means to simultaneously provide readable information and deter would-be counterfeiters through the crafting of difficult-to-reproduce printing effects. This allows the brand owner to select the best printing technology for the deterrents (or for different aspects of a multi-region deterrent), and to gain insight into how the counterfeiter may attempt to reproduce their deterrent with a different printing approach. In this paper, we consider repeated line patterns (to test print quality), 2D bar code reading, and authentication of a color deterrent (color tile). We print these features using thermal inkjet (TIJ), dry electrophotography (DEP) and liquid electrophotography (LEP) digital printers. Color tiles demonstrate the printer's color fidelity and are used to show authentication accuracy on multiple printers. 2D barcodes demonstrate the printer's binary print quality, and also test different capture settings and substrates for printing. In this way, we test different printers, different inks, different substrates different reading devices and settings along with different security printing deterrent characteristics. Finally, we introduce and discuss meaningful metrics for comparison, including security payload density, deterrent reproducibility, color and spatial frequency fidelity, deterrent pre-compensation and the sensitivity of deterrent authentication to image capture settings and devices.
Steven J. Simske, Jason S. Aronoff, Margaret Sturgill, Galia Golodetz, "Security Printing Deterrents: A Comparison of TIJ, DEP and LEP Printing" in Proc. IS&T Int'l Conf. on Digital Printing Technologies and Digital Fabrication (NIP23), 2007, pp 543 - 548, https://doi.org/10.2352/ISSN.2169-4451.2007.23.1.art00009_2