The term 'scale' refers to 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. '1/35th'). 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 1/35th scale model tank is 1/35th the size of the actual vehicle upon which the model is based. Models generally make no attempt to replicate scale weight, only size.
Scales for commercially produced kits include 1/9, 1/16, 1/24, 1/35, 1/48, 1/72, 1/87 (railroad HO scale), 1/144, 1/250 and 1/300. However, 1/35 and 1/72 are by far the most popular. A relatively new trend led by Tamiya is military vehicle kits in 1/48 scale — a popular scale for military aircraft models. 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.
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 and half-tracks, 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. Vehicles of this time period are considered to be experimental for the most part and did not make major contributions to what few battles they took part in.
Vehicles used between 1939 and 1945 fall into the Second World War category. Even though this area spans the shortest number of years, it is by far the most popular for armor modellers due to the enormous range of vehicles used and the vast improvements in armor technology. During the early part of the war, most armored vehicles were smaller, less heavily armored, and lightly armed. Major tank engagements early on convinced governments on all sides of the need for more survivable and deadlier vehicles.
Any vehicle serving in a setting after 1945 is considered "modern". This encompasses a longer time span and very large number of armor designs from all countries.
Models may also be categorized by place of service, for example, US or Soviet. They may also bve categorized by function, for example, combat engineering vehicles, recovery vehicles, etc. In all cases, the national and unit markings on the replica determine the era and user nationality. For example, a model of a Sherman tank, a World War II design, would be considered a 'modern' model if the tank were shown in Israeli markings from the Six-Day War. The same vehicle in World War II US Army markings would be considered a World War II Allied subject.
Models are generally built with historical accuracy in mind, and each model may represent many hours of research effort on the part of the modeler. Frequently, modelers display some of their research work alongside their model.
There is generally some crossover of modelers between the eras, though some focus solely on a specific era, country of origin/operation, or even to a specific vehicle.
Parts are produced by injection of liquid styrene plastic under very high pressure into complex steel molds. These molds are generally composed of two halves that sandwich the parts; however, 'slide molds' may consist of many steel components to allow greater levels of detail to be incorporated into a single sprue. Once the plastic cools, it is removed from the mold. In the 1960s and 1970s, typical vehicle kits might contain 50 to 200 individual parts. Today it is common for a single vehicle kit to contain from 300 to 1200 parts. Each part must be carefully cut from the 'sprue' (the plastic channels that allow the plastic to flow into the mold and which hold the parts in place), cleaned of any flaws or mold marks, and then assembled.
Instructions consist of paper booklets or sheets supplied with each kit. Usually, instructions show drawings of the parts. A recent trend has been the use of photographs rather than drawings, but these types of instructions have not proven popular and may be declining in use. For a kit with hundreds of parts, good instructions are vital. Flaws in instructions are not uncommon.
Markings for the model usually are provided as decals.
Models built 'out of the box' are built according to kit instructions, using no materials except those provided in the kit itself. In the past, there was some tendency to view 'out of the box' builds as simpler or of a lower standard of detail than modified kits (see below). However, recent trends in which kits contain over 1,000 individual pieces including parts from plastic, etched brass, and aluminum have given new meaning to the 'out of the box' build. Today, a stock kit can be very highly detailed.
Customized kits are typically built by more experienced modelers who take a kit and add components, either scratchbuilt or commercial conversion or aftermarket accessories. Such models may be more highly detailed than a straight build 'out of the box' though the trend to more detailed kits is decreasing the difference. The term 'kitbashing' denotes models built using parts from more than one kit to make a single, more accurate or different model. Many armor modelers engage in the use of aftermarket sets and built from scratch (scratchbuilt) parts to make their models more accurate or simply unique. In extreme, master-level cases, a model with hundreds of kit components may be detailed with several hundred additional commercial and home-fabricated parts to reach a very high level of realism.
Scratchbuilt models are those for which no kit exists; highly skilled modelers create their vehicle from sheet plastic and components they fabricate themselves. Some scratchbuilt models may contain a few commercial components, but typically it is a small proportion of all the model's parts.
Several companies produce armor model kits, the most famous of which are Airfix, Dragon Models Limited, Tamiya, Trumpeter, Academy, Hobby Fan, Italeri, Revell-Germany/Monogram and AFV Club. The focus of many manufacturers of late has been to increase the accuracy of their kits and provide alternative types of material such as photo etch details, turned metal barrels, and cast metal parts.
Aftermarket markings are also available. Firms such as Archer Dry Transfers or Decalomaniacs produce stand-alone sheets of wet or dry transfer markings to allow the modeler to complete a different or more accurate variant.
Several organizations and publications exist to support and promote the hobby of modeling military vehicles. The Armor Modeling and Preservation Society or AMPS is a 800-plus member organization devoted to the hobby. The International Plastic Model Society supports modelers of all types including military vehicle modelers. The Miniature Armoured Fighting Vehicle Association (MAFVA) is a UK-based military vehicle modeling group.
Commercial publications devoted to or including military vehicle modeling include ModelX, AFVModeller, Military Miniatures In Review (MMIR), Armour Modelling, and Military Modelling.