Fig. 5
a Surface FTIR-ATR spectra of zinc white (B/P = 30) in linseed oil with 5% (w/w) Siccative de Haarlem after treatment in the Weather-O-Meter for 500 h with 40% (v/v) 13CO2(g) and 70–80% RH. Reference spectra are given for b the same oil film before treatment, c Zn13C2O4·2H2O and d Zn12C2O4·2H2O. Green lines indicate characteristic 12C-zinc oxalate IR absorption bands