Trompe L'oeil

Trompe L'oeil is a French word, directly translating to "deceive the eye", is traditionally an art technique used to create an optical illusion in which a flat surface appears to be three dimensional. 

More precisely in the context of silverware, it is often utilised to describe the surface of silver items that depict a wood-like finish (such as birch). Most common examples are found in Russian works of Silver by silversmiths such as Pavel Ovchinnikov.