Fig. 3

Laser-induced PL spectroscopy of different analysis points of the cartonage: a red-pink painted area (point 1 in Fig. 2) (λ_max 615 nm), flesh tones (point 2 in Fig. 2) (λ_max 590 nm) following excitation at 355 nm. The PL emission spectrum of an area painted with dark colours (point 3 in Fig. 2) (λ_max 920 nm) resembles the spectral features of Egyptian blue