Their is much more behind the Mona Lisa than we see. Using special x-rays we are able to see many thin layers of paint underneath the top layer of paint on the Mona Lisa. About 40 different layers have been discovered. Da Vinci did this on purpose as his intention was to create a sort of smoky or blurring the outlines of the figure. This is known as "sfumato" from the Italian word "fumo" (meaning smoke). He did this by laying down a thin glaze and smearing it with his finger. This gave the painting a more three dimensional effect. Each one of these layers is about 1-2 micro meters, about 50 times thinner than the human hair.
One of the Mona Lisa biggest mysteries is her smile. It seems as though it glows. Using the same x-ray machine they noticed the sfumato effect in the smile. Using contrasting colors gave the smile a certain glowing effect. This effect took many years to complete. The whole painting took around four years to complete. The sfumato effect is seen all through the painting and gives it a very life like feeling. Using the sfumato effect has given the Mona Lisa her very interesting look and smile.
Nathan D. Period 1