Principles of Camouflage, WWII Tactical and Technical Trends, No. 37, November 4, 1943 (Lone Sentry)

Camouflage became a major military tactic in the first World War when the French formed a "section de camouflage" and the British organized their own camouflage service as a unit of the Royal Engineers. In 1917 with the growing submarine peril, "dazzle painting" of war vessels and merchant ships was commonly applied. Since then a specially trained corps of experts in camouflage has been maintained by the armed forces of all countries. With the development of air power, the branches and services of this activity have grown in importance.

The following report contains some interesting material as developed at the British Camouflage Training Center in the Middle East and stresses the theoretical side of camouflage and its application in nature and in war.

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Attention is called to the growing tendency, especially in the Middle East Theater, towards offensive, and away from defensive camouflages. In the battle of El Alamein and in subsequent battles of the British 8th Army during the past year, the offensive nature of camouflage technique has been noticeable.

The following summaries of the different divisions cover briefly the theoretical background, the application in nature and the application in war.

The fundamentals of camouflage as given in the school may be set down in six different divisions as indicated in the appropriate letter designations shown herewith.

a. Similar Color (or Background Resemblance)

(1) Theoretical Aspect

Every solid object appears in the field of vision as a patch of color differing more or less markedly both in hue and brightness from its surroundings. Such differences of color and tone provide the main clues which enable the eye to record, and the brain to perceive, an object's presence and identity.

It therefore follows that an important step towards the reduction of visibility or conspicuousness of any object lies in the modification of its color and tone to harmonize as closely as possible with its immediate surroundings.

(2) Application in Nature

The principle of color resemblance, or assimilated coloring, is widely employed in nature. Every major environment with a dominant type of color affords innumerable examples of the principle--different members of the fauna wearing a concealing dress or uniform closely matching the surrounding country.

In the snowlands, white is the color employed by many mammals and birds such as the snowy owl, Greenland falcon, polar bear, and American polar hare. In the surface waters of the sea, blues, greens and grays predominate on the bodies of fishes such as the mackerel, tuna, herring and others. In the stony or sandy desert, light cinnamon, ochre, buff and sandy colors are found to be those worn by animals belonging to many groups--including birds (such as the desert larks, sand grouse, bustards, nightjars), mammals (such as the small African fox, jackal, jerboa), and many lizards, snakes and insects. Finally, in the evergreen foliage of tropical rain forests, green is the color usually adopted, as illustrated by many parrots, parakeets, fruit pigeons, woodpeckers, tree lizards, tree frogs, tree snakes, and innumerable smaller forms such as beetles, praying mantis, leaf insects, grasshoppers, caterpillars and spiders.

A number of animals undergo a seasonal color change that is correlated with changes in their surroundings, as exhibited, for example, by the ptarmigan, and mountain hare, which in the spring shed their white winter colors and become brown or gray. Others such as flat fishes, squids, and certain lizards are capable of rapid, and sometimes almost instantaneous color change in accordance with the color of the background against which they come to rest.

(3) Application to War

The principle of color resemblance has obviously wide possibilities on military camouflage, and it is one which should never be neglected as a first and fundamental step towards reducing the visibility of any target--from the largest to the smallest--whether it be a large installation or a tent, a railway or a small artillery piece, a tank or an individual soldier.

The color to be used will depend upon the predominant color of the surrounding country. For obvious reasons, the principle can be applied with greatest effect in the case of static targets, since mobility is bound to involve some changes in the color of the background against which an object is likely to be seen or photographed.

In such circumstances, the advisability of changing the color must not be overlooked. A gun or vehicle colored for cultivated surroundings in Europe will be an extremely conspicuous object in the Western Desert; so will a khaki-clad soldier when seen against the snow.

One of the devices most frequently employed in natural camouflage is that which is known as cryptic coloration. A cryptically colored animal is one which is so tinted and patterned that it is very difficult to see when viewed against its natural background, for example, the zebra or tiger.

No cryptic coloration can be devised which is effective in all circumstances. When an object is so colored that it is conspicuous against its surroundings by reason of its hue, there are two methods of concealment:

(a) To move the object to a background of suitable color, or

(b) To change the coloration of the object.

Most cryptically colored animals have an instinctive tendency to resort to right background and there to remain motionless as long as they wish to be hidden. It is not enough, however, to resemble the background simply in color and pattern; a cryptically colored object must be so oriented that its pattern is coincident with that of the background, which, therefore, brings in behavior.

b. Behavior

(1) Theoretical Aspect

Frequent association, in the mind, of the physical make-up, actions and associated features of an object, allows one to immediately distinguish the object subsequently when observing only a portion of the characteristics--the mind supplying the missing characteristics.

If, however, as in camouflage, an object is cryptically colored and placed on a suitable background but is not oriented correctly, if its movements do not conform to that which it is supposed to resemble, or, if its tracks are not the tracks of the object it is supposed to be, a question is raised immediately in one's mind and, by deduction, the true identity may be ascertained.

(2) Application in Nature

In nature, animals, insects, fish, and birds are disguised and sometimes resort to false behavior to mislead their enemies in defense, and their prey in offense.

Among animals, when the object to be imitated is normally motionless, the disguised creature also remains that way, thereby achieving some advantage such as food or safety. If the object copied is one which is usually in motion, for example weeds or leaves drifting in water, the animal imitates these movements with great exactness.

(3) Application in War

The application in war can be for defense or offense. It follows then, that when supplies and material especially, are cryptically colored and against a suitable ground, the object simulated must be followed in every detail; for example, a truck camouflaged to look like a haystack moving across the landscape and leaving tracks behind it, does not act as a haystack normally does and is therefore quickly detected.

c. Countershading

(1) Theoretical Aspect

Countershading is a system of compensating coloration whose function is to counteract and nullify the visual effects of light and shade. The effect of countershading is to produce on a solid object an illusory appearance of flatness.

Owing to the effect of unequal illumination falling upon its different surfaces, a solid object of uniform color presents to the eye the well-known appearance of light-and-shade, or relief, to which is due its appearance of solidity. By this means alone an object can be distinguished as a solid form even when it is placed before a background whose color and texture exactly match its own.

When any solid body is observed in its natural state its upper surfaces seem to be more brightly illuminated than its lower surfaces. This is because in nature the source of light is from the sun and the effect of this top lighting is to lighten the tone of the upper surfaces, while the lower parts, being in shade, appear darker.

By the use of paints or colorings and darkening the upper surfaces, and lightening those beneath and grading the tones on the sides from the dark to the light, it is possible to counteract the effect of the natural light and shade, and thus render a rounded body apparently flat. By careful countershading in this manner an object will become completely invisible at a short distance when placed before a suitable background.

(2) Application in Nature

Countershading is a concealing medium commonly found in nature such as the coloration of wild animals, the majority of mammals, birds, reptiles and fishes being colored darkest on the back, white on the belly, with intermediate tones graded round the flanks.

(3) Application in War

In military camouflage this principle of countershading is applicable to objects of all sizes. Upper surfaces should be painted and textured so as to conform to the color and tone of the surrounding country (background) and the sides graded and toned from this to the white which the under surfaces and parts in shade should be painted.

d. Disruption

(1) Theoretical Aspects

Observation of distant objects shows that their visibility depends upon their forming a continuous patch of color, bounded by a specific outline, which stands out more or less conspicuously against a darker or lighter background.

The eye is more readily attracted to circular markings and secondly to straight regular lines or symmetry, than to irregular lines, for in nature straight regular lines seldom exist. However, where in nature they do practically exist, nature has absorbed them in disruptive coloring.

When a combination of circles and straight lines are put together in a given manner they immediately suggest to the mind the distinguishing features of a certain object, i.e., the outline of a truck as seen from a distance is composed of definite straight and curved lines, which immediately call to one's mind that it is a truck and not a house.

Due to the natural intermingling of light waves reflected from an object and recorded by the eye or camera, greater differences in color are necessary for resolving them into their recognized elements. Likewise structural outline may be fortified by paralleling the shape with a lighter or darker color, or it may be diminished by cutting across the structural outline (disruption). The value of disruptive patterning depends upon its ability to nullify those clues upon which the eye depends for recognition by breaking up the visible continuity of surface and the regular outline which bounds it, thus transforming what is really a continuous surface into what appears to be a number of discontinuous surfaces and distracting attention from the object as a whole.

(2) Application in Nature

Application of disruption may be found in all forms of life, one of which is the very common marking stripes which pass from the bodies to the limbs or wings of many wild animals, fishes, birds, and insects.

A common structural disruptive pattern may be seen in the zebra. The black marks of the zebra are close to right angles with the outline it presents when seen at a distance, and similarly, the stripes on frogs, which pass from the body to the two leg portions when in contracted position.

(3) Application in War

Application of disruptive coloration in war may be made to any object of military importance.

In general, elements of a disruptive pattern should be carried across adjacent surfaces of an object; e.g., from the roof to the walls of a building; from the hull into the upper parts of a ship. Such patterns cause discontinuous surfaces to appear continuous, whereas a break in the pattern at construction points emphasizes the very features which it is desired to obliterate.

e. Elimination of Shadow

(1) Theoretical Aspect

Shadow may be cast or retained by a surface, the shadow cast being a lessening in the intensity of light reflected from a surface because of an object between the light source and the major reflecting plane. The retained shadow represents the areas of shadow on the surface of, or within, an object, due to the obstruction or exclusion of light by structural features; such as the dark interior of a vehicle seen through a window or back curtains, or the inside of a tent, seen through the open tent flaps.

Since shadow is caused by necessary structural design, and shadow is recorded by the eye or camera because of absence of light, its obliteration may be obtained by including it in a non-significant pattern of an applied medium. Such medium itself reflects less light and thereby becomes less recognizable.

(2) Application in Nature

One of the most common applications of shadow elimination in nature is that of camouflaging the eyes of all forms of wild life. Those forms of wild life which depend upon natural camouflage for protection have a black or dark brown irregular patch which includes the eye and passes across the structural shape of the body. (Certain fowl extend their wings to the ground to include their body shadow.)

(3) Application in War

A special application of this principle is seen in the use of patterns to conceal typical structural details which, without proper treatment, are liable to provide a clue to recognition. Such features are the dark patches seen under the chassis and mudguards of vehicles; the box-like recesses above the rear wheels of trucks; outline of shadow on track guard of tanks; elimination of ground shadow of buildings and structure, etc. The visible shape of such patches may be distorted by their inclusion within a dark patch of color of non-significant shape, so that the tell-tale clues to recognition are no longer present.

f. Features

(1) Theoretical Aspect

Disguise--visual deception--is effected not by the concealment of the existence of an object, but by the concealment of its nature or by the suggestion with dummies of objects or activities calculated to mislead the enemy. Disguise is the most specialized of all camouflage activities which depend upon it ultimately, for their success. Disguise is never confined to mimicry in appearance only: it is also a matter of deportment (in nature) and organized discipline (in war).

(2) Application in Nature

In nature, disguise may be defensive or aggressive in function, either serving to deceive a hunter as to the nature, posture, or whereabouts of his prey; or allowing the hunter to approach, to ambush, or to allure his quarry undetected. In the first case, the misleading appearance will deter or deflect attack by potential enemies; in the second, it will facilitate the capture of prospective victims.

Those features of disguise of a passive or defensive function may be found in caterpillars, stick-insects, etc., which simulate the appearance of twigs, certain tree frogs and moths which resemble the bark of trees, crabs and fishes resembling sea-weed.

Those whose function it is to draw attack away from a vital target to a non-vital target or dummy objective may be observed in butterflies with dummy eyes on their wing tips, which deflect attack by birds away from the head to a non-vital part of the body.

Those whose function is bluff, intimidation and threat may be found in various animals which resemble other animals feared by their own enemies, e.g., certain caterpillars which when being attacked resemble snakes; various insects which display large eye-like markings on their wings; various beetles and spiders which resemble, in appearance and habits, ants and wasps which are distasteful or dangerous to their natural enemies; other spiders which prey upon the ants which they themselves resemble.

Those features of disguise which have an aggressive function may be classified for approach, ambush or allurement.

Disguise which enables an animal to approach its prey or enemy undetected, through resemblance to some object which is not feared or suspected, may be found in certain fish, chameleons, and praying mantes which resemble leaves and are able to approach their prey without being recognized.

Disguise which offers static concealment, or ambush may be found in ant-lion larvae which trap their prey from a concealed position dug in the sand; certain large frogs which cover themselves with sand and leaves and thus surprise prey approaching within striking distance.

Disguise which suggests an object, a target, attractive to a hunter, or to an enemy, and thus draws attack where it can suddenly and effectively be countered, may be found in various fishes which, though while camouflaged, attract their prey towards themselves by displaying a bait, e.g., having the tongue converted into a dummy worm; praying mantes resemble a flower and thus attract the insects upon which they feed.

(3) Application in War

Disguise in war as well as in nature can play a defensive or offensive function and follows in the same sequence as presented above in nature.

Those passive or defensive features of camouflage may change an object to appear like something innocuous or of no interest to the enemy; e.g., defended houses and pill boxes resembling native dwellings, haystacks, etc., observation posts constructed in dummy tree stumps, dummy dead horses or men, etc. Or, disguise whose function it is to draw attack away from a vital target to a non-vital or dummy objective; e.g., dummy dumps, gun positions, decoy fires, etc.

Those features of disguise whose purpose it is to bluff, intimidate or create a threat may be made of dummies or other types of deceptive devices--in defense to delay, or prevent attack by creating a false impression of force; or in an offensive role--to mislead the enemy as to present dispositions or future intentions; e.g., dummy defensive positions, dummy tanks or other material, and other deceptive contrivances which give the appearance of units or formations where none exist.

Those features of disguise which have an aggressive function for approach, ambush, or allurement may be found in such forms as: (for disguised approach;) the Trojan horse, sun shields and sniper suits.

For ambush, such installations as antitank guns in quick-release tent coverings, heavy machine guns in quick release brush covering, etc; and, in allurement or decoy, such disguise as mystery ships; feigned retreats; and all forms of "booby traps".