Like all other things, the design of human head is also a secret unsolved. As one of not too many who face variety of human faces daily, not only I am familiar with, but further I tried to use some of these ideas to explain hidden ideas in words, it works well generally.
For instance, why does Da Vinci in his Mona Lisa use 3/4 view instead of full frontal angle? Because it is more artistic one may say. But why so? For existing answer one can say that angle create movement. That is not all answers.
Once one is aware of some of these design principles, he is in a better position to turn out a unique work.
For Sargent, he likes to use side light while Zorn, from both sides sometimes. Why?
Source of methods and techniques of painting is from the deep mystery of the spiritual world. It contains growing and changing orderly and regularity, including the form of the world and profound rationale. The painting theory rose to philosophy, which commands painting theory. Rise from painting technique to close to Tao, in order to create a high-level work.
