Ten white and light cow hide samples were finished with a fluorescent brighthening agent-contg. nanopigment (0.3-0.5 mu m) and studied for resistance against UV irradn. 2,5-Thiophenodiylbis(5-tert-butyl)-1,3-benzoxazole was prepd. according to Z. Hu at al. (2008) and used as the agent.