Casein plaque with moulded head of Napoleon Bonaparte, c 1900.

Commemorative black circular plaque of Emperor Napoleon Bonaparte (1769-1821), engraved by F Muller and made of casein, a semi-synthetic plastic made from milk. It had various commercial names including Galalith in Germany and Erinoid in Britain and was used to make furniture handles, buttons, laminates and other decorative items.