Art Authentication in the Past
Up until thirty or forty years ago, the methods for detecting a forged artwork relied on the expertise of art historians. People could study the brush strokes used in a painting and compare them to the known works of a famous artist. Professionals also studied the small details of a painting, like eyes and fingers, and compared them with the techniques used in other paintings. Experts could also examine the craquelure, the fine cracks that oil paintings develop over many years, so they could see if the painting was too new to be a true work from an old master.