Here is an assignment from one of our more advanced lessons in Workshop J, submitted by Luz. The assignment is designed to help you understand an important aspect of notan: gradations.
Comment from Luz:
I found this exercise harder than I thought and highly enlightening. I never look at gradations on a painting.
Notans are not necessarily flat areas of one value but involve gradual changes of value. You need to take into account these gradations when designing your notans. Learn more about edge notans in lesson J01 Gradation & Edge Notans.
For a brief introduction to the key concepts, see: The Virtual Art Academy® Beginners Guide To Notan