EMT SCB1X/SCB2X brightening base film is a surface-modified polyester film made from polyethylene terephthalate by melt casting, biaxial stretching and orientation by in-line treatment with a coating treatment device. The product is coated on both sides, with good optical properties, good flatness, high adhesion, good temperature resistance and good apparent quality. This product is mainly applicable to the manufacture of prism film and composite film for LCD.