Recently I was going through some old notes and binders of papers, and I ran across this handout. I originally recieved this at a Portrait painting seminar/workshop about seven years ago and one artists handed it out as part of his demo.
I am trying to find out where this comes from. I am pretty sure it is from a book, if anybody knows which please contact me and let me know.
Here is a pdf of the handout. Portrait handout