The vivid red hue color has been known as a feature of Vincent van Gogh famous paintings, Wheat stack under the cloudy sky. However, the mineral compound that makes the red color contained in the paint fades upon its exposure to light, making the painting colors lighter over time. Some say that the vibrant painting reflects his complex personality and without the vividness, the painting has lost that value.
"Normally, the idea is these paintings are there for a hundred years, or five hundred years, and they're static - nothing really changes," says Koen Janssens from the University of Antwerp, Belgium. "But the opposite is actually true when you look in detail," he further remarked
The paint is not an ordinary one. It is the first human-made synthetic paint called plumbonacrite or the red lead, which after the research by Belgium researchers, known to degrade when exposed to light. The researchers managed to take a tiny piece of a white speck among the wheat field and under the microscope, using x-ray lasers, he found the speck was made of red minerals. The speck used to be red.
Apparently Vincent liked to use the paints for the bold colors, which became the characteristic of his paintings, on his 2000 painting works during 10 years of his most productive lifetime. For that reason the vibrant colors of many of his paintings, slowly fades away upon the light exposure.
This is not the first time scientists found such an occurrence. Renior's painting of Madame Léon Clapisson of which the making dates back in 1883 also had the same occurrence. However, for this one, the trigger isn't the red mineral, but it's an insect named a cochineal. It separates the inorganic and organic compounds when exposed to light, making the red turn a mellow gray color over time.
This is a challenge for scientists to find the better methods to preserve great painter artists' works of art as well as to return the colors to the paintings.
