Materials and surfaces can be made fluorescent by admixing optical brightening agents (OBAs). Optical brightening agents are fluorescent substances that absorb light in the UV wavelength range from 300 to 390 nm, and emit it in the adjacent spectral range from 400 to 460 nm.
Materials containing added OBAs appear whiter or brighter and more luminous. They are used in some papers, textiles, detergents and plastics. A UV light source is needed to observe fluorescent surfaces. Depending on version, both our Color Viewing Light viewing booths and our multiLight colour proof lights are equipped with UV lamps, in addition to the standard illuminants. The simultaneous activation of D50 or D65 and UV permits reliable assessment of optically brightened materials. The visual impression is determined by the amount of OBAs used and the UV component emitted by the light source. Viewing jobs using UV light are frequently encountered in the textiles sector or in security printing. However, OBAs are nowadays also used in a wide variety of other materials, such as imitation leather, paints or films, meaning that their testing is also acquiring ever-greater importance.