The story of Da Vinci painting eggs is a household name. This Renaissance master, when he first began to study art, was asked by his teacher, Verrocchio, to paint eggs for a long period of time in order to observe the light and shadow changes of objects in minute detail, and practice the basic skills of painting. This seemingly boring experience, however, benefited Da Vinci for the rest of his life. His works are characterized by rich and varied lines that blend hardness with softness. He was especially skilled at using diagonal lines of varying density to express the subtle changes between light and dark.