Da Vinci

You probably don't know this, but I'm taking college classes.  Today I had to go to class and part of today's topic was Leonardo Da Vinci.  The professor spent a lot of time talking about two of his paintings: The Last Supper and the Mona Lisa.  I learned a lot of things that I never knew (I cannot claim to be a great connoisseur of art).  My professor explained that a couple years ago modern technology took a look at what was under the Mona Lisa.  They thought maybe there was another painting underneath, but there wasn't.  What they DID find, however, was that before Da Vinci painted the garment that Mona's wearing, he painted a slip on her first.  So, in essence, he "dressed" her in a slip, then painted the dress over the slip.  My professor thought this brilliant...I thought it rather strange.