Optical brighteners, optical brightening agents (OBAs), fluorescent brightening agents (FBAs), or fluorescent whitening agents (FWAs), are chemical compounds that absorb light in the ultraviolet and violet region (usually 340-370 nm) of the electromagnetic spectrum, and re-emit light in the blue region (typically 420-470 nm) by fluorescence. These additives are often used to enhance the appearance of color of fabric and paper, causing a "whitening" effect; they make intrinsically yellow/orange materials look less so, by compensating the deficit in blue and purple light reflected by the material, with the blue and purple optical emission of the fluorophore. Optical brightening agents (OBAs) are chemicals that are added to everything from linen slacks and silk blouses to socks and underwear. They use the process of fluorescence to trick your eyes into believing your clothes are whiter and brighter than they actually are. To ensure your garments enhance and retain this whiter than white appearance, many laundry detergents contain optical brighteners, too. APPLICATION Clear and pigmented lacquers Paints Molded thermoplastics Films and sheets Printing inks Synthetic leather Ultraviolet tracer Photo processing solutions Adhesives Fibers Thin layer chromatography (TLC) Overprint varnishes Printing inks