The finishing technique called “grunge polishing” is a watchmaking decoration that creates a matte and shiny effect. It is particularly appreciated because it is very flat. It is mainly used in the artisanal method on bridges and components that come into contact with the mainplate. The technique is achieved using an emery stone, sometimes also referred to as a “chocolate stone,” without adding an abrasive paste. The polishing movements are done in different directions, which creates a smudge texture with micro-scratches on it from the rough surface of the stone.