Fig. 9
SEM–EDS analysis of cross-sectional samples taken from nine overlapping color-areas: a Blue + bean green, b light red, c charcoal gray, d black–brown, e maroon, f deep red. Note: The SEM–EDS spectrum corresponding to the analyzed points of a specific layer are marked in violet, red, or green. 1, 2, 3 and 4 represent the layer sequence and the analysis points of the layers of these sections. The SEM images are correlated in sections a, d, e, f, and g in Fig. 8. See Supplementary Materials 3 for the EDS spectra