The Woman Behind Glass

Leonardo da Vinci started the Mona Lisa around 1503 and may have worked on it for over a decade. The subject is likely Lisa Gherardini, wife of Florentine silk merchant Francesco del Giocondo — hence the Italian name La Gioconda. She was nobody particularly important, which makes the painting's fame even stranger.

Leonardo used a technique called sfumato — ultra-thin layers of translucent paint that create soft, smoky transitions. There are no hard outlines on the Mona Lisa's face. Her features seem to shift depending on where you focus, which is why her expression appears to change as you look at it. Everything strange about the smile traces back to this technique.