In this portrait painting tutorial, realist painter Alex Tzavaras shows you to paint the planes of the head. In portraiture, the term “plane” refers to a change in direction on the surface of the head. As the head turns towards or away from a light source, there will be a change in tonal value from light to dark. So whenever we try to creat the 3D appearance of the head when oil painting, being able to identify the different planes of the face and head is very important. It’s also essential for achieving a painterly appearance in your work, by painting each plane with bold separate brushstrokes.