Guess the Artist

Your clues this week are:

• Though this is a drawing and the artist is best known for painting, the first formal art instruction this French artist received was in sculpture.
• More than anyone had before, the artist studied color theory and optical effects by reading chemical and mathematical treatises.
• A major influence on the artist was the 1827 book Essay on the Unmistakable Signs of Art by the author -- and I am not making this up -- Humbert de Superville.
  
  And
  
  
• The medium (Conté crayon) and support (Michallet paper) seen above are important clues. Michallet paper has two sides: smooth and ribbed, with a heavy "tooth." The artist always used the toothy side.

Please email me your guesses over the coming week. I'll post the winner and correct answer with next week's guessing game. Good luck!

Last Week's Answer:

Tui was the first person to email the correct answer: Jean-Étienne Liotard (1702-1789). By the way, last week's picture was actually a trompe l'oeil painting. Kudos, Tui!