Barye was a prolific artist and famous for his 'animalier' sculptures. He liked to have control over all aspects of production and spent much time experimenting with patination. His surface colours ranged from rich velvety browns to deep antique greens. Patination is the process of artificially colouring the surface of the metal or changing its appearance. True patina is created by chemical changes to the surface through long exposure to the elements. Artificial patina is created through the application of drying oils, resins, pigments or acids to protect the surface or to enhance or change the colour of the metal. Heat is sometimes used in this process. The surface can also be enriched by adding gold (‘gilding’) or silver.