• Geometry plays an important role in drawing the light – seeing the lit area as geometric shapes makes it easier to sketch them roughly. Observe the areas of light.  What shape or combination of shapes does the light create(i.e. the rectangular shape of her lit nose or the triangle of her cheekbone)? Focus on one area at a time but follow with a connected area so that in the end a whole image is formed out of the individual shapes.
• Have a student model sitting in the middle of the room with a single light source shining at an angle. The other students observe the model from slightly different viewpoints.  Using colored pencils, each student draws what is seen from their viewpoint and focuses on the shapes that form the eye, mouth, cheek areas, etc.  
• As they continue to build with shapes of light, students will start to notice the definition of the whole subject emerging.
• Analyze the portrait using mathematical relationships, connecting and communicating mathematical ideas to describe the portrait in a written composition.
• Compare and contrast the use of light in Gentileschi’s portrait with students’ portraits.

Born in Pisa, Gentileschi moved to Rome and, by the age of 20, began to study painting. He was one of the few artists to work with the tempestuous master painter Michelangelo Merisi da Caravaggio (1573–1610). Gentileschi developed his own style and a reputation that earned him the opportunity to paint for Marie de Médicis in Paris. In 1626 Gentileschi moved to England where he became court painter to Charles I. Gentileschi lived in England for the remainder of his life.

This young woman holding a scroll and leaning against a slab bearing hieroglyphics is a sibyl. In ancient Greek literature and legend a sibyl is a woman with the gift of prophecy. The young woman here wears a turban, which identifies her as a sibyl, and holds a scroll on which her prophecies are recorded. The name sibyl, taken from a specific woman hailing from Asia Minor, was first mentioned in the writings of the Greek philosopher Heraclitus. By the end of the 1st century B.C. there are ten different sibyls on record, each linked to a famous oracular shrine of the ancient world. By the end of the Middle Ages, the Church had accepted twelve different sibyls, all associated with the coming of Christ.

This solid young woman, a physical type often painted by Gentileschi, is thought to be the artist’s daughter, the talented and successful artist Artemisia Gentileschi. Her calm, direct gaze speaks of a tender familiarity between the artist and sitter. If the model truly is Artemisia, this adds another layer of meaning to the painting. At the age of 19 Artemisia was allegedly raped, and during the trial she voluntarily submitted to a torturous test in which metal rings were tightened around her fingers in order to prove the truth of her accusation. This particular device for establishing the truth was called “the sibyls.”

Gentileschi’s paintings typically include few figures placed prominently in the composition. He was known for his use of sumptuous materials, as seen in the orange brocade cloth that drapes across the woman’s body. Other signatures of Gentileschi’s style include his meticulous attention to hands and face and the sibyl’s pose, with her upturned gaze and twisting body.

Gentileschi was a member of a group of 17th-century artists called “Caravaggisti,” painters who imitated the style and methods of the influential 17th-century Italian painter Caravaggio. Gentileschi incorporated Caravaggio’s use of chiaroscuro (Italian meaning bright-dark) into his painting, creating intense effects of light and shade. In Portrait of a Young Woman as a Sibyl the figure, placed against a dark background, is lit from the right side, highlighting her hands and face and the folds of elaborate drapery.