Patent ID: 8385640

Claim:
A system for controlling a printed dynamic optical illusion image, comprising: an item including the printed dynamic optical illusion image having one or more mutable portions that can be switched between first and second appearance states by application of an appropriate external stimulus, such that when the one or more mutable portions are in the first appearance state the printed optical illusion image has a first illusion state, and when the one or more mutable portions are in the second appearance state the printed optical illusion image has a second illusion state, wherein changing the printed dynamic optical illusion image from the first illusion state to the second illusion state affects the perception of an optical illusion by a human observer; a stimulus source for providing the external stimulus; and a controller for controlling the stimulus source; wherein the printed dynamic optical illusion image was printed on a print media by a printing device using a plurality of colorants, one or more of the colorants being appearance mutable colorants having spectral characteristics that can be switched between a first colorant state and a second colorant state by applying the appropriate external stimulus, the one or more mutable portions of the optical illusion image being printed using at least one appearance mutable colorant, such that the printed optical illusion image is switchable between the first and second illusion states by applying the appropriate external stimulus to switch the one or more appearance mutable colorants between their first and second colorant states, thereby switching the mutable portions of the printed optical illusion image between their corresponding first and second appearance states.