Shading and surface form

What colour are shadows and shading?

This POST provides a link to “Shading  and surface form”, Chapter 27 of my book “Painting with Light and Colour”. It may surprise many that it comes in PART 2, which is dedicated to painting with colour. The reason is that the visual systems that are used to create colour consider blacks, whites and greys to be colours and, accordingly, they treat the blackness, greyness and whiteness of shadows, shading and highlights as colour.

Surface-solidity, spatial-separation and ambient-allumination

However, this fact of visual perception does not mean that the reflected-light does not provide information to other visual systems, working in parallel. In particular, the systems that tell us about surface-solidity, spatial-separation and ambient-illumination continue to perform their function. As explained in PART ONE of this volume, although they enable us to sense these properties, they never make them visible in the way body-colour is visible.

The problem of invisibity

The “invisibility” of these properties confronts artists trying to represent them with the seemingly insoluble problem of deceiving the eye/brain into “seeing” something that they cannot see. Luckily due to the research of Seurat, Cézanne, Bonnard, Marian Bohusz-Szyszko and others, a simple and, accordingly, practical resolution of this seeming paradox is available. Moreover, due to research undertaken by myself and colleagues, its efficacy can be explained in scientific terms (see many chapters in Book One of this volume and Chapters 13 and 14 of “What Scientists can Learn from Artists”)

The solution

The practical solution provided to me by Professor Bohusz-Szyszko is to ensure (a) that there should be no repetitions of colour in any part of the surface of paintings and (b) that all the paint that is actually visible to viewers of the painting should be made up of mixtures containing some proportion, however small, of complementary or near-complementary, pigment colours. In this conntext,  it is important to emphasise  that this solution should be kept in mind when painting shadows, shading and highlights.


Two images and a question to consider

Cowslips and violets

Flowers in a vase

Question: Do all the “mistakes” and inconsistencies in the “flowers in vase” painting matter?

Other relevant chapters from Book 2: “Painting with Colour”

Other relevant Posts on colour and light in painting:

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One thought on “Shading and surface form”

  1. I found Chapter 27 profoundly interesting and can’t wait to read Chapter 28. I was struck by how the mark-making of the artists conveyed intensity and feeling in their sketches. It provided me with a new appreciation of the importance of lighting/shading and markings in sketches. I would think this would be especially true when using sketches as the basis of the ultimate impact and outcome of a finished picture.

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