Leonardo da Vinci. Portrait of Isabella d’Este. 1499.  

Isabella d’Este wanted to have the best possible portrait of herself painted, so  in 1498 she determined to surround herself with the most eminent contemporary artists and find the best portrait painter, one who could produce a perfect imitation of nature; her choice fell on Leonardo da Vinci. When in Venice, Leonardo da Vinci showed his portrait of Isabella to his friend Lorenzo da Pavia, who wrote to the Marchesa: “Leonardo da Vinci is in Venice, he has shown me a portrait of Your Ladyship that is very lifelike. It is very well done and could not possibly be better.” Despite Isabella’s insistence, the painting was never done. In his sketch, Leonardo used various pigments (sanguine and chalk), different tones of black, and finely hatched and smudged red and yellow ochre to obtain the passage from light to shadow on the face and hair. A very pale white applied to the bosom (covered by a piece of lace called a “modesty piece”), the forehead, and the cheek, accentuates the slant of the shoulders and the shadow of the neck. -Louvre