OF SELECTING THE LIGHT WHICH GIVES MOST GRACE TO FACES.

If you should have a court yard that you can at pleasure cover with
a linen awning that light will be good. Or when you want to take a
portrait do it in dull weather, or as evening falls, making the
sitter stand with his back to one of the walls of the court yard.
Note in the streets, as evening falls, the faces of the men and
women, and when the weather is dull, what softness and delicacy you
may perceive in them. Hence, Oh Painter! have a court arranged with
the walls tinted black and a narrow roof projecting within the
walls. It should be 10 braccia wide and 20 braccia long and 10
braccia high and covered with a linen awning; or else paint a work
towards evening or when it is cloudy or misty, and this is a perfect
light.

On various helps in preparing a picture (521-530).