 4, was launched in 1932, followed in 1936 by a range of model aircraft kits made from cellulose acetate, which were the world's first.Polystyrene models were introduced in 1955, which offered kits of aircraft, ships and cars in various scales.By the 1970s, Frog's catalogue included a large number of lesser-known aircraft types, manufactured only by the company, as well as a number of ship kits.