Fig. 3

FTIR-ATR spectra of zinc white in four different oil binding media (B/P = 30) after treatment in the Weather-O-Meter for 300 h and RH = 80%. The asterisk spectrum in each figure (a–d) shows the measurement on the surface of the oil film while the black square spectrum below was obtained from the backside. Reference spectra of the oil film before treatment (black triangle) and of zinc oxalate (black circle) are also shown. Green lines highlight characteristic zinc oxalate IR absorption bands