A sign is fabricated which presents different messages depending on the angle of view. The fabricated sign has walls, different sides having parts of different messages. The method of fabrication includes taking at least two images, cutting them into strips of equal width and combining successive strips...http://www.google.com.au/patents/US4255380?utm_source=gb-gplus-sharePatent US4255380 - Method and apparatus for manufacturing signs or the like carrying information which is different for different viewing angles
