Sand (sometimes also called sandpaper) is a type of paper used to make the surface of the objects more refined by rubbing one of the sand surfaces that have been added rough material to the surface of the object .
Amplas is a kind of work tool made of paper or cloth that has been added with rough materials such as granular sand so it is sometimes referred to as sand paper. Sandpaper serves to make the surface of the rough objects become smoother by rubbing the surface of the roughness to the surface of a material or object.