Face=painting is usually pretty low stakes, but the militaries of the world approach it as an important challenge. How best to make a face look like anything but?
As Dr. Christopher Larsen of the One Shepherd Leadership Institute demonstrates, thousands of years of evolution has trained humanity to recognize the structure of our faces, so the best bet is to try to exaggerate those features to the point where they're no longer recognizable.
This video shows three different styles of hiding the human face with paint: American, British, and South Korean.
The Americans go for balanced offsets, the British go for splotches, the South Koreans prefer bold stripes. The idea is to have no skin showing and to have the top of the head covered in a hat. Camouflage has changed a lot throughout the years, but the need to keep bodies from looking like bodies has proven to be timeless.