|The same engraving of a sphere (twice), but the right one is inverted.|
As is increasingly being confirmed by current brain research, the Gestalt psychologists were right. They claimed that we as humans share certain perceptual inclinations that are hard-wired or innate—they "come in the box" with the rest of the brain. These are inborn universal traits, neither culture-laden nor unique.
Now that people think of "art" as all but exclusively having to do with individuality and self-expression, artists rarely talk about the traits that we inherently share, including these fundamental organizing tendencies. In contrast, graphic designers (whose temperament is in between artists and architects) use them constantly and, for the most part, are well aware of how they work. In fact, these same tendencies are the basis for all the age-old ploys in conjuring (sleight of hand and stage magic), pickpocketing—and, of course, in camouflage. Chief among them are similarity and proximity grouping, edge alignment, continuity, closure and so on.
Nobel Prize neuroscientist Eric Kandel talks about these tendencies (he calls them "bottom-up processing") in relation to current brain research in his amazingly wide-ranging book, The Age of Insight: The Quest to Understand the Unconscious in Art, Mind and Brain (NH: Random House, 2012). As he explains, when we look at objects or drawings of things, we come with the assumption that the source of light is overhead. As a result (as shown above), if two identical images of a shaded sphere are placed together, but one of them (the sphere on the right) has been vertically flipped, the other one (which is seemingly lit from above) looks spherical, expansive and solid. The one lit from the bottom looks deflated, less substantial and concave.
|Solomon J. Solomon, Pencil drawing of a hand (c1910)|
Artists and designers, even the earliest cave artists, seem always to have known this, the traditional technical name for which is shading. It is of great importance because it is such a reliable way to make flat drawings (which are merely marks on paper) appear to be three-dimensional shapes that bulge out in space toward the viewer. A particularly skillful example of this is a drawing of a hand (above) by British painter Solomon J. Solomon (1860-1927), from his book The Practice of Oil Painting and Drawing (London: Seeley, 1910).
Solomon was an uncle of the American playwright Moss Hart. Interestingly, he was also the person put in charge during World War I of the British Camouflage Section within the Royal Engineers (1916-18).
Solomon is often credited with the use of overhanging nets, garnished with burlap strips, so that anything beneath them will be visually broken up by irregular shadows—just as happens on the tennis court, when the shadows of the chain link fence disrupt the shape of the ball in the grass. It is also commonly said that he and his camouflage unit devised the first British steel-lined observation post, designed to look exactly like a dead tree on the battlefield.
|Examples of countershading from Camoupedia (2009)|
Years in advance of WWI, a prominent American artist, Abbott H. Thayer, revealed how inverted shading (commonly called countershading) contributes in a major way to "protective coloration" (or animal camouflage). An avid naturalist as well as an artist, it was Thayer's belief that there is a functional reason why so many animals have "white undersides" (light-colored bellies, with darker coloring toward the top)—not unlike the coloring of the sphere on the right at the top of this page. As a result, countershaded animals look less dimensional, even flat. I have discussed this in detail, in print as well as online.
If an artist can apply shading to a shape on a flat surface, so that it looks three-dimensional, then the exact opposite can also be done: Shading can be painted out and inverse shading painted in, so that a truly dimensional form looks flat and insubstantial. Here's how Thayer's son and collaborator, Gerald H. Thayer explained it:
If a rounded object, say a ball or cylinder…is to be made to disappear, it has, in the first place to be countershaded. That is, its shadowed parts must be lighter in color, must be painted lighter until the shadow no longer shows; and the portions facing toward the source of light must be just proportionately darkened. In this way, a rounded, solid form can be made to look perfectly flat.
The elder Thayer demonstrated this repeatedly. Sometimes he used artificial lighting and stuffed animals, such as the tiger he set up a Harvard University (as shown above, the third row down). Lighted from below (on the left), the animal is clearly visible, but it virtually disappears (on the right) when lighted from above. Thayer's more portable standard way of showing the effects of countershading was to "paint out" wooden duck decoys (or short of that, sweet potatoes). In the bottom photo, he claims that there are two decoys, but we only see one. The one on the left (clearly visible) is the color of the ground but has not been countershaded, while the one on the right (which I can't find) has been expertly countershaded.
• For more information, see this annotated bibliography on Art, Architecture and Modern Camouflage.