A method of generating a variable demetallized pattern in a holographic web and a security device using such method. A holographic microstructure pattern is imparted to an oligomer disposed on a surface of a substrate. A metal layer, such as aluminum, is deposited to the holographic microstructure pattern of the substrate and then covered with a variable resist pattern. The variable demetallized pattern in the holographic web is then generated by removing the metal layer not covered by said variable resist pattern.