File Name : supplementary figure 1.jpg

Caption : lslc fitting (red) of intact (para)realgar particle in the lower part of the paint layer in coorte sample (spectrum 6d) to the references orpiment and gypsum with r = 0.00290 (a), realgar and gypsum with r = 0.01454 (b), and para-realgar and gypsum with r = 0.02529 (c).