Optical brightener masterbatches are added to polymers to improve their appearance by reducing yellowing, increasing whiteness, and enhancing brightness. These masterbatches work by absorbing light in the UV spectrum and emitting it in the visible range, which gives products a brighter and fresher look. Many plastic materials have a tendency to yellow due to degradation by UV or visible light during processing. The breakdown products absorb blue light, giving a yellow appearance in daylight. Optical brighteners work by absorbing light in the UV spectrum and emitting it in the blue range of the visible spectrum, resulting in a brighter, fresher appearance. Optical brightener masterbatch is the brightest among all the masterbatches, making it suitable for numerous applications.