A series of model aircraft plastic kits, in 1:72 scale, launched in 1955 by Lines Bros and which seized production early 1960s.
Founded in 1931 by Charles Wilmot and Joe Mansour, International Model Aircraft Ltd. (IMA) originally used the Frog brand name (said to stand for "Flies Right Off the Ground") on the Interceptor Mk.4 semi-scale rubber-band powered flying model, launched the following year. Also in 1932, a marketing partnership with the toy company Lines Bros Ltd. was formed and other Frog brand flying models followed. In 1936, a range of 1:72 scale aircraft models in kit or pre-built form, moulded in cellulose acetate, was launched under the Frog Penguin name (alluding to the non-flying nature of these models). These were the world's first plastic model construction kits. An early release was the No.21P Empire Flying Boat, issued in 1938.
During the Second World War, the company produced flying models for target purposes and 1:72 scale aircraft recognition models. The Penguin range was dropped in 1949 but a new range of Frog polystyrene kits was introduced in 1955. A wide variety of aircraft, ship and car subjects in various scales were issued during the 1950s and 60s, 1:72 scale being standardised on from 1963 onwards for aircraft models, Frog's 1:72 lineup including a large number of lesser known aircraft types that were not available from any other manufacturer at the time, such as the Avro Shackleton, Martin Baltimore and Maryland, Vultee Vengeance, Curtiss Tomahawk, Blackburn Shark and Skua, Bristol 138 and Beaufort, Tupolev SB2, Supermarine Attacker and Scimitar, Armstrong Whitworth Whitley, Gloster Javelin, de Havilland Vampire, Hornet, and DH 110, Dewoitine D.520, Macchi MC202 Folgore, Fokker D21, Hawker Sea Fury and Tempest, Fairey Gannet, Barracuda and Firefly, General Aircraft Hotspur, Focke-Wulf Ta 152H, Messerschmitt Me 410, Arado Ar 234, Heinkel He 162, Dornier Do 335, Heinkel He 219, Gloster E.28/39, North American Mustang II, Vickers Vimy, Ryan NYP "Spirit of St Louis", de Havilland Gypsy Moth "Jason", and the Westland Wallace. Production of scale and non-scale flying models continued into the early 1960s. In addition to aircraft models, Frog also produced a number of ship kits, four examples being the MV Shell Welder coastal oil tanker, the THLV South Goodwin Lightship, HMS Tiger, and an RNLI lifeboat.
Frog also produced a line of larger-sized aircraft as 1:96 scale models, subjects including the Bristol Britannia, Douglas DC-7, Vickers Valiant, Avro Vulcan, Handley Page Victor, de Havilland Comet, and the Vickers Viscount.
In 1971, IMA's parent company, now Tri-ang, entered receivership and was acquired by Dunbee-Combex-Marx the following year. During the mid-1970s, some of the Frog kit moulds were transferred to various factories in the Soviet Union and the kits began to re-appear under the Novo brand name. Moulds of Second World War Axis Powers subjects were acquired by Revell around 1977, the Axis types having been declined by Novo. Moulds of many jet aircraft were acquired by Hasegawa.
The last Frog-branded kits were produced in 1976. In more recent years, some ex-Frog/Novo kits have been re-issued by Revell and various East European manufacturers.