Documents of value including intaglio printed transitory images

摘要

An imprint of inked intaglio pattern elements such as lines on a document of value or the like, including background portions and readily recognizable image portions each formed by pattern elements of the imprint. The pattern elements forming the image portions differ in orientation or depth from pattern elements forming the background portion to provide variation in contrast between image and background with change in angle of view of the document, the pattern elements being so arranged that the image blends visually with the background from one angle of view but appears as a readily recognizable symbol in clear contrast to the background from another angle of view.