How Do Paintings Age Without Fading?

When you look at a painting in a museum, it looks bright and new. But why doesn't the red turn pink or the blue fade to grey after 100 years? It is because of a special recipe made by artists long ago.

Artists mix pigment powder with a sticky liquid called oil. This oil acts like glue. When it dries, it hardens into a tough skin that holds the color particles tightly in place. Imagine pressing sand into wet cement; once dry, the sand cannot blow away.

Some paints are stronger than others. Lightfastness is the word for how well paint resists the sun's rays. If you leave a blue shirt outside too long, it gets pale. But oil paints have heavy metal atoms that act like tiny umbrellas, blocking the sun from washing out the color.

Sometimes old paintings look darker because the clear coat on top turns yellow. This is not bad; it just means the paint is getting a tan! Conservators can gently wash off this old layer to reveal the bright colors underneath.