ERDL pattern

ERDL pattern, also known as Leaf pattern, is a camouflage pattern developed by the United States Army at its Engineer Research & Development Laboratories (ERDL) in 1948. It was not issued to elite reconnaissance and special operations units until early 1967, during the Vietnam War.

The pattern consists of four colors printed in an interlocking pattern.

The pattern was initially produced in a lime-dominant colorway, consisting of large organic shapes in mid green and brown, black ‘branches’, and light green ‘leaf highlights’. Shortly thereafter a brown-dominant scheme (with the light green replaced by light tan) was manufactured. The two patterns are also unofficially known as "Lowland" and "Highland" ERDL, respectively.

The ERDL pattern was used on official and unofficial U.S. Military garments in Southeast Asia (SEA), in both ground and aviation garment versions, from 1967 to the war's end.

On official ground combat garments, the ERDL pattern was first applied to the Tropical Combat Uniform (third model) around 1967, and was printed onto to a lightweight cotton poplin textile material. This poplin uniform was very short-lived, but it did see combat use in SEA by various U.S. Special Operations and some other units. Soon afterwards, the ERDL pattern was again applied to the Tropical Combat Uniform (third model), but was printed onto the standard rip-stop cotton textile material. This ERDL rip-stop cotton Tropical Combat Uniform version thus saw wide use in SEA after 1968, with Special Operations units and also regular units, especially as ground combat operations continued throughout the war up to late 1972.

On official aviation combat garments, the ERDL pattern was used on the USAF Type K-2B Flying Coveralls, in a cotton poplin textile version. The USAF ERDL Coveralls saw some use in SEA from 1967-69, until replaced by the USAF Nomex Coveralls in 1970. The Navy also produced an official ERDL aviation garment in their Flying Coverall 'MIL-C-5390G' pattern, produced in a cotton twill textile. This Navy ERDL Coveralls saw very limited SEA use from 1967-68, as their Nomex Coveralls were already in use.

On unofficial and commercial garments, the ERDL pattern was copied and used by U.S. commercial textile manufacturers in the late 1960s, and applied to various commercial camouflage garments for hunting or unofficial military use. Some commercial ERDL garment examples were made using cotton poplin material, and others were made in the standard rip-stop cotton material. Many commercial ERDL garment examples of the time were made in the pattern mirroring the U.S. Military OG-107 Fatigue Uniform, with a standard tucked-in shirt, and conventional trousers design. These commercial ERDL OG-107 Fatigue-style garments did see some combat use in SEA, such as with U.S. Navy tactical jet aviators in the 1968 timeframe. Some USAF aviators also purchased local/in-country tailor made ERDL garments and Coveralls, for combat and off-duty use.

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