Abstract: This invention is directed to improvements in substrates, such as paper, incorporating a security device, and to documents made therefrom. The security substrate comprises at least one elongate security device, which security device has a series of first regions exposed at a series of windows formed in at least a first surface of the substrate and a series of second regions covered by the substrate at bridges formed between the windows in the first surface of the substrate. Each of the first regions is provided with a first security feature which is substantially of the same appearance in each region and is visible in each window when the first surface of the substrate is viewed ire reflected light.

Abstract: A method of forming a decoding device to enable hidden information or indicia on an article to be revealed is described. The method comprises electronically transferring data defining the decoding device from a central source (3) to a remote site (6). The decoding device is created at the remote site (6) using the transmitted data.