Most copied stage illusion

Invented by Robert Harbin (South Africa) in 1965, the Zig Zag girl is the most popularly performed stage illusion in the world. A girl, standing in an upright cabinet, is apparantly cut into three pieces and has the middle of her body pulled to one side. It was copied so quickly that Harbin published a highly- priced book in 1970 (limited to 500 copies) which allowed each purchaser to build one version of the prop. It is estimated that at least 15,000 Zig Zag illusions have been built to date, meaning that 14,500 are unauthorised copies.