proceed the strict inspection to acid etched raw materials,and choose the material suppliers(such as raw sheet,glass etching power,etc) strictly according to the enterprise standard of HR/BM001-2004. 2M Far away from products,the granularity rate is over 98% through eyes. one side acid etching,no water mark or dirt on the other side,no damage of four edges,no scae of both sides. Non-stain standard.