Notan could be one of most important elements of a painting, or drawing.
Notan is a Japanese term that best describes the light and dark structure, or patterning, as a way of expressing beauty, and harmony.
A strong Notan arrangement in an artwork tends to grab and hold our attention.
When a painting works in black and white it should also work in colour. If the Notan/design/ composition is strong, the need for excessive detail, or literal accuracy, is reduced.
Rembrandt A woman bathing. 1654
Look at the strong Notan In Rembrandts A Woman Bathing.
Forgetting the middle grey for a moment, these will be referred to as lights. Look how the large light area of the woman's clothing is the focal point and the angle of the arm to the left , leads the viewers eye up and across the shoulder to the head and then back down the right of the picture to the smaller notes of light, and accross the legs into the subtle background. the dark's are the equally important counter to this movement. They isolate the smaller light notes or become isolated themselves withing the larger light areas, giving a push and pull rhythm.
A painting that lacks a pleasing arrangement of light and dark will look weak and uninteresting to the viewer. It is this Notan structure that we should look for in our subject and should be the target, right from the earliest stages of our work.
I have reduced some well known works to a black and white arrangement to demonstrate my point.
Berthe Morisot Manet 1872
A pleasing Notan arrangement is also something that should be sought out in a scene if you are taking your painting outdoors. This can be spotted more easily if you squint down and reduce what you see to the major light and dark grouping.
As many of us artists know, there is often a real benefit in learning how to simplify what we are looking at. At times it is necessary to completely omit or move some of what we see in front of us in order to improve the pictorial arrangment.
Without divulging too much here, I believe copying what we see is a really great start and a noble pursuit, but from here, we should try to understand more fully, the basic elements that make up natures' beauty.
To attempt to copy Gods handy work with paints, and then to further limit it to 4 sides of a canvas would be to grossly underestimate and compromise it.
Camille Corot ville-d'avray 1870
So, it's useful to understand enough of what we see before us and combine this knowledge into a simplified whole. This approach is more effective in engaging the viewer, allowing them to complete the picture in their minds eye and imagine for themselves, something of that place.
Similar to how a good book can describe a place and invoke our own ideals of what that is like. A granular and technical description would, most likely, bore us, and our imagination would no longer be involved.
Therefor. it should not be deemed arrogant or affected for artists to take what's needed from a scene and eliminate anything that detracts from the overall goal - of delighting the viewer.
Notan is not to be confused with the gradation of tone, or the pushing of form (the stretch of light to dark) which is, of course, important, but it is, rather, referring to the structure, or initial placement of the overall light and dark pattern.
With the risk of sounding repetitive: without a strong Notan, no matter how well rendered a subject is, the artwork would lack the all important punch of a powerful design finding itself, like so many other works that nobody cares to talk about, filed away, under mediocre.
If the intended subject lacks an interesting Notan it is best to move on, or in the case of a still life or portrait, to adjust the lighting, type of objects or clothing. You can of course invent or exaggerate but this is likely to give you unnecessary difficulties.
I would strongly recommend a book on Composition by Arthur Wesley Dow.
where the application of the qualities of good design i.e Opposition/Transition/Subordination/Repetition/Symmetry are demonstrated achieving a solid and unified design.
I would also recommend Michael Britton Resources at Art Academy.com.
How to Practice Your Notan Arrangements.
One of the best ways to develop a good taste for strong Notan design, is to look at past artists who understood this quality.
If you have Photoshop, or similar software, try picking a work you think has a strong sense of design and reduce it to black and white (or view through deeply squinted eyes), print it out and pin it somewhere you can view it easily.
copy it using just black and white, with any medium of choice and a larger than usual brush - DO NOT BOTHER WITH DETAIL as this will defeat the object!!
Copying from past masterworks is a sure fire way of solidifying your understanding and ensuring it manifests itself in your own work.
Finally, remember, there are no rules. Don't allow anything you have read, or heard, hinder your inquisitive nature. Just keep it in mind and familiarize yourself with good design by studying and/or copying and go from there.