Notan is a Japanese word that means “lightness-darkness.” It represents one of the basic principles that help compositions stick to the wall. Notan has nothing to do with local or chosen colour. It’s the ability to see things in terms of black and white, and to consequently build strength in imagery. When compositions work in black and white — they work.
Whether they put a name to it or not, artists in all cultures have long recognized the value of notan.