Model military vehicles range in size and complexity; from simplified small-scale models for wargaming, to large, super-detailed renditions of specific real-life vehicles. Scales The 'scale' is the proportion of actual size the replica or model represents. Scale is usually expressed as a ratio (e.g. '1:35') or as a fraction (e.g. '1/35'). In either case it conveys the notion that the replica or model is accurately scaled in all visible proportions from a full-size prototype object. Thus a 1:35 scale model tank is 1/35 the size of the actual vehicle upon which the model is based. Models generally make no attempt to replicate scale weight, only size. The most popular scales, by far, are 1:35 and 1:72. Other less-commonly used scales for commercially produced kits include: 1:1, 1:6, 1:9 ("Traditional" scale), 1:12, 1:16 (RC tanks, scale model kits), 1:24, 1:25, 1:30, 1:32, 1:48, 1:50, 1:64, 1:87 (railroad HO scale), 1:144, 1:250, 1:285, 1:300, and 1:350. A relatively recent trend led by Tamiya is military vehicle kits in 1:48 scale – a popular scale for military aircraft models. The scale was formerly introduced by companies such as Aurora, and Bandai in the 1970s. However, the scale did not gain popularity mostly because of the accuracy and detail of the scale. Scratchbuilt models may be in any scale but tend to follow the most popular kit scales due to the ease of finding kit components which may be used in the scratchbuilt model. Larger-scale models tend to incorporate higher levels of detail, but even smaller-scale models may be quite intricate. Subjects Military vehicle modelers build a wide variety of models. Tanks and other armored fighting vehicles are the most popular subjects at model contests. Modelers also build ordnance, military trucks, tractors, half-tracks, artillery, and lighter vehicles such as jeeps and motorcycles. Models may be displayed in stand-alone mode, that is, with no base, or on a decorative base, often with a label of some kind. More elaborate bases may include scale scenery, intended to depict the setting in which the vehicle served. This trends towards the closely related hobby of diorama building. Modelers tend to focus on vehicles from three eras: World War I, World War II, and the modern era. The first denotes armored vehicles from their inception into combat during the first World War until approximately 1939. Many vehicles of this time period may be considered to be experimental and few