Vectograph

A vectograph is a type of stereoscopic print or transparency viewed by using the polarized 3D glasses most commonly associated with projected 3D motion pictures.

Credit for the concept of the vectograph is due to Joseph Mahler, cousin of famed composer and conductor Gustav Mahler. He immigrated to the U.S. from Czechoslovakia in 1938 and was hired by the Polaroid Corporation, where he worked with its founder, inventor Edwin Land, to develop his idea into a practical process.