ecent research indicates that the green pigment known as atacamite, which was found in samples dating as far back as the end of the 12th dynasty, is likely a degradation product of artificial copper pigments. It appears that green pigments were not commonly used before the New Kingdom. The discolouration of pigments, including red, is attributed to the interaction of salts with the pigment components, catalyzing deterioration. The red pigment has suffered significant fragility and stability issues, with cracks and loss of cohesion, some of which can be attributed to cracks in the underlying limestone support.