2.5" x 3.5" Oil on 300lb hot pressed smooth watercolor paper. I was curious as to how oil painted on a smooth surface since my normal oil paintings are on primed canvas that still has a bit of tooth. Another thing that I had to do that normally I do not, is thin my paints. My pencil undersketch resembled the famous painting much more closely than the oil portrait. Even my smallest brushes seemed too large for the facial details. I may attempt painting her again in the future after buying some smaller brushes. I am at the moment working on recreating a life sized reproduction of the Mona Lisa as well. I am recording my progress as I go along and shall post it in the tutorial section when finished. Here is a link to a larger than life sized view of the piece > http://www.johnhoulefineart.com/ATCMonaLisaI.html