Fig. 6

L’Annonciation. a Distribution of lead soaps obtained by integrating the lead carboxylate peak in the R-FTIR spectrum (1576–1480 cm⁻¹). b Distribution of lead soaps obtained by integrating the lead carboxylate peak in the ATR-FTIR spectrum (1557–1475 cm⁻¹). c Distribution of lead white obtained by integrating the carbonate band in the R-FTIR spectrum (1484–1325 cm⁻¹). d Distribution of lead white obtained by integrating the carbonate band in the ATR-FTIR spectrum (1472–1265 cm⁻¹)