In all of Leonardo’s many sketchbooks and writings, there is no mention of the Mona Lisa, nor any preliminary sketches of this painting.
No one knows the exact year that Da Vinci completed the Mona Lisa, but most agree that he started painting it in 1503 or 1504 and worked on it for several years, maybe as much as a decade, carrying it with him wherever he went. Some say he died without ever finishing it. The Mona Lisa is now over 500 years old!
The Mona Lisa was painted with oil paint on a poplar wood panel, using a technique that left no visible brush marks.