Fig. 8: Determination of the volume fraction of Cu-rich phases in EB.

Each row shows a different embedded and polished raw pigment sample acquired from the House of the Painters at Work. a Backscattered electron micrograph with the measured area outlined in orange. b Corresponding EDS elemental maps (Ca, Si, Cu). c Binarized Cu maps and d calculated area percentages of Cu- and non-Cu-containing phases (average values reported on the right).