A method for producing a three-dimensional object having selected elements which are colored differently than other elements of the object comprising the steps of: (a) providing a film of a photohardenable composition containing a photoresponsive agent; (b) irradiating the film in a cross-sectional...http://www.google.de/patents/US5677107?utm_source=gb-gplus-sharePatent US5677107 - Production of three-dimensional objects
