A method, system for encoding or decoding information in physical properties of an object. A tangible product comprises a three dimensional tangible object having modified physical properties; and wherein the modified physical properties are a modification of physical properties, wherein the modification encodes information. A method comprising: obtaining a representation of a three dimensional object having physical properties; obtaining information to encode; determining modified physical properties by modifying the physical properties to encode within the modified physical properties the information; and producing a tangible product, wherein the tangible product is the three dimensional object having the modified physical properties.