VOLUME HOLOGRAM COMPRISING EXPANSION AGENT LAYER OR CONTRACTION AGENT LAYER FOR CREATING COLOR PATTERNS

摘要

The invention relates to a security element in the form of a multi-layer foil body containing a volume hologram layer (3) which is accommodated using a relief hologram (4). The Bragg grating of the volume hologram is expanded (8) locally using an expansion agent (5) or a contraction agent, in the form of a color image, for example, in order to add a second piece of optional information. A pattern, such as an image, is created either by partially imprinting the expansion agent or using an inserted mask layer (6) that is locally pervious to the expansion agent.