"Crown" brand Emery is manufactured under controlled conditions from selected bauxite , unlike natural emery which is mined from earth's crust as it is. Due to this, "Crown" emery is able to maintain consistency in it's quality with respect to the corundum content, crystal size, and crystal shape. These properties are very important for a longer lasting and powerful abrasive material.
This is followed by careful classification of the material into different grain sizes following various standards such as IS, BS, FEPA and JIS. Abrasive grains with uniform grain size distribution give faster and required cut , whereas material with undersized and oversizes grains reduce the efficiency of the grains to polish and result in unwanted scratches respectively, as far as surface finishing is concerned.