UV Absorber Tinuvin 328 Type (Benzotriazole)

A UV absorber (UVA) such as Tinuvin 328 works by absorbing harmful UV radiation (290–380 nm) and converting it into harmless heat before it can initiate photodegradation in the binder or substrate. A HALS (hindered amine light stabilizer) does not absorb UV; instead it scavenges the free radicals generated once UV-initiated degradation has begun. Best practice is to use both together: the UVA intercepts UV energy at the surface, while HALS quenches any radicals that form deeper in the film. This synergistic combination significantly outperforms either additive used alone.