Optical brighteners, optical brightening agents (OBAs), fluorescent brightening agents (FBAs), los yog fluorescent whitening agents (FWAs), yog cov tshuaj sib txuas uas nqus lub teeb hauv thaj tsam ultraviolet thiab violet (feem ntau 340-370nm) ntawm electromagnetic spectrum, thiab re -emit lub teeb nyob rau hauv cheeb tsam xiav (feem ntau 420-470nm) los ntawm fluorescence.Cov additives no feem ntau siv los txhim kho cov tsos ntawm cov xim ntawm cov ntaub thiab ntawv, ua rau 'whitening' nyhuv;lawv ua rau cov khoom siv daj / txiv kab ntxwv zoo li tsawg dua, los ntawm kev them nyiaj rau qhov tsis txaus ntawm xiav thiab ntshav lub teeb pom los ntawm cov khoom siv, nrog rau xiav thiab ntshav qhov muag pom ntawm fluorophore.