Fig. 6From: The influence of light and relative humidity on the formation of epsomite in cadmium yellow and French ultramarine modern oil paintsLight microscopy imaging of W&N French ultramarine paint samples under ageing conditions: a 50% RH ambient light, oil-primed canvas; b 75% RH, elevated light conditions, oil-primed canvas; c 75% RH, elevated light conditions, acrylic-primed canvas; d 75% RH, near-dark conditions, acrylic-primed canvasBack to article page