Why is the Mona Lisa considered to be a “masterpiece”?
The Mona Lisa is probably the most famous painting in the world. (I googled it today and there are more than 7 million pages referring to it). It is remarkable because of its enigmatic character. It is very beautiful, but it is not known exactly who was the model for it. It was one of the earliest painting in which a light perspective (“sfumato”), creating an impression of a foggy atmosphere, was applied. It was painted ca. 1503 – 1504. The painting is masterful because there are almost no visible brushmarks. There is a comprehensive article on the painting on wikipedia that provides a good start for research: http://en.wikipedia.