Method for providing dynamic optical illusion images

A method for providing a printed dynamic optical illusion image having first and second illusion states, comprising:

• receiving a specification of a dynamic optical illusion image having one or more mutable portions with at least two appearance states, such that when the mutable portions are in a first appearance state the optical illusion image has a first illusion state, and when the mutable portions are in a second appearance state the optical illusion image has a second illusion state, wherein changing the optical illusion image from the first illusion state to the second illusion state affects the perception of an optical illusion by a human observer;
• and
• using a printing device to print the dynamic optical illusion image on a print media using a plurality of colorants, wherein one or more of the colorants are appearance mutable colorants having spectral characteristics that can switch between a first colorant state and a second colorant state by application of an appropriate external stimulus provided by an external stimulus source, wherein the mutable portions of the optical illusion image are printed using at least one appearance mutable colorant;
• wherein the printed optical illusion image can switch between the first and second illusion states by applying the appropriate external stimulus that switches 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;
• wherein the appearance mutable colorants include dyes or pigments that undergo a chemical change in response to the application of the external stimulus to switch between the first colorant state and the second colorant state.