A detailed study has been made of the photoprotective effect afforded to wool fabric against irradiation (by simulated sunlight or natural sunlight through glass) by the 2-(2'-hydroxyaryl)-2H-benzothazole ultraviolet absorber, sulfonated Tinuvin P. The degree of photoprotection depends on the amount of absorber applied to the wool and the pH at which it is applied. Wool dyed with representative acid dyes was also protected to a significant extent by the absorber against both phototendering and dye fading.