Optical Brightener CBS-X is mainly used in laundry detergents to make clothes look whiter and brighter. It can also be added to other materials where the same effect is desired. They convert UV light to enhance blue light and reduce the yellow light. This makes the whites look whiter and the colors look brighter. They are commonly referred to as Fluorescent Brighteners. Other areas of use include: soap, washing powder, water based coatings, nylon, wool, paper, and cotton. Usage is 0.05 to 0.5%, depending on application.