Abstract: A security device that increases the number of design options available for a machine testable security feature formed in part from a light absorbing (e.g., magnetic) material, while more effectively hiding or concealing this material, is provided. The inventive security device achieves these results by physically separating this security feature from a visually detectable or public security feature. Also provided by way of this invention is a process for preparing the inventive security device as well as a security document that employs one or more such devices.

Abstract: Durable security devices that are resistant to chemical attack and mechanical degradation and security articles employing such devices, are provided. By way of the durable security device of the present invention, opposing longitudinal borders adjacent an information-bearing layer are sealed, thereby preventing corrosive and/or degrading materials from reaching this layer through these sealed borders. In a preferred embodiment, at least a portion of the information-bearing layer is fully encapsulated, thereby rendering this portion or layer and the information conveyed thereby, impervious to chemical attack.