Optical Brightening Ageng (OBA)

The optical brightening agent (OBA) absorbs invisible UV radiation and emits in the visible range. This can create reflectance values of more than 100%, i.e. at specific wavelengths more light is reflected by the sample than had come in at these wavelengths. This effect is utilized in white papers or textiles, where blue light is excited. The CIE whiteness correlates better to the visual assessment than ISO whiteness, since the entire visual range is taken into consideration.