Fig. 7

Normalised ATR-FTIR spectra for W&N French ultramarine paint samples on acrylic-primed canvas after ageing conditions a 50% RH in ambient light conditions; b 75% RH in elevated light conditions; c 75% RH in near-dark conditions

Normalised ATR-FTIR spectra for W&N French ultramarine paint samples on acrylic-primed canvas after ageing conditions a 50% RH in ambient light conditions; b 75% RH in elevated light conditions; c 75% RH in near-dark conditions