Polarized films are made through pre-treatment of cleansing and swelling a raw material, optical PVA, and through post-treatment of dyeing with dichroic direct dye or iodine, and drafting.

Because of the features of the raw material and the subsidiary materials, the property of polarization is given to the films. In order to prevent contamination by dusts or impurities, all the processing is carried out in a clean room.