Cleaning of the surface of a work is usually done for aesthetic reasons, but in reality the cleaning of the surface protects the work of further wear. The aim of the procedure is to remove non-original layers from the surface, like stains, deposits or layers affecting the object's appearance, texture, or transparency. Cleaning offers the viewer a better aesthetic appearance of the sculpture, and protects the work itself against damage. It is done either by mechanical means (tools, special laser devices, steam, micro-sandblasting) or chemically (with agents that remove or neutralize pollutants)..