Thayer is sometimes referred to as the “father of camouflage.” This is not entirely unreasonable, because, while he did not invent camouflage, he was undoubtedly one of the first to write about certain aspects of it, including disruptive camouflage to break up an object's outlines, of masquerade, as when a butterfly mimics a leaf, and especially of countershading.
Beginning in 1892, he wrote about the function of countershading in nature, by which forms appear less round and less solid through inverted shading, by which he accounted for the white undersides of animals. This finding is still accepted widely, and is sometimes now called Thayer’s Law. However, he became obsessed with the idea that all animals are camouflaged, spoiling his case by arguing that conspicuous birds like peacocks and flamingoes were in fact cryptically colored. He was vigorously attacked for this in a long paper by Theodore Roosevelt.
He first became involved in military camouflage in 1898, during the Spanish-American War, when he and his friend George de Forest Brush proposed the use of protective coloration on American ships, using countershading. While the war did not last long enough for anything to be done about this, the two artists did obtain a patent for their idea in 1902, titled “Process of Treating the Outsides of Ships, etc., for Making Them Less Visible” (U.S. Patent 715,013), in which their method is described as having been modeled on the coloration of a seagull.
Thayer and Brush’s experiments with camouflage continued into World War I, both collaboratively and separately. Early during that war, for example, Brush developed a transparent airplane, while Thayer continued his interest in disruptive or high-difference camouflage, which was not unlike what British ship camouflage designer Norman Wilkinson would call dazzle camouflage (a term that may have been inspired by Thayer's writings, which referred to disruptive patterns in nature as “razzle dazzle”.)
Gradually, Thayer and Brush entrusted their camouflage work to the responsibility of their sons. Concealing-Coloration in the Animal Kingdom (1909), which had taken seven years to prepare, was credited to Thayer’s son, Gerald. At about the same time, Thayer once again proposed ship camouflage to the U.S. Navy (and was again unsuccessful), this time working not with Brush, but with Brush's son, Gerome (named in honor of his father's teacher).
A few years later, with the start of World War I, Thayer made proposals to the British War Office, trying unsuccessfully to persuade them to adopt a disruptively patterned field service uniform, in place of monochrome khaki. Meanwhile, Thayer and Gerome Brush’s proposal for the use of countershading in ship camouflage was approved for use on American ships, and a handful of Thayer enthusiasts (among them Barry Faulkner and other Thayer students) recruited hundreds of artists to join the American Camouflage Corps.
Read more about this topic: Abbott Handerson Thayer