Chainmail is a material used to make armour, and consist of small rings of metal put together to form a mesh. Chainmail has been used at least since the time of the Roman Empire, and was an important armour material up until fully articulated plate armour became available. Several ways of linking the rings together have been known since ancient times, the most common being the 1-to-4 pattern where each ring is linked with four others.
In Europe, the 1-to-4 pattern was almost completely dominant, with 1-to-6 being seen very rarely. In East Asia (primarily Japan), chainmail was also common, but here several more patterns were utilized and an entire nomenclature developed around them. In the Middle East, yet other patterns were developed and often combined with metal plates linked in with the rings.
Historically, the rings composing a chainmail armour would be riveted or welded shut, to reduce the chance of the rings splitting open when subjected to a thrusting attack or a hit by an arrow.
In modern reenactment and LRP, split sprung steel washers are used. Usually a two pairs of pliers are used to bend the washers open and closed whilst "knitting" the chainmail. The resulting mail is usually heavier than traditional wire-wound mail.
In tests during the World War I, chainmail was tested as a material for bullet proof vests, but results were unsatisfactory, as the rings would fragment and further aggravate the damage. Chainmail fringe was also added to helmets to protect the face but this proved unpopular.
In many films, chainmail is sometimes substituted for by knitted cloth spray painted with a metallic paint. There are also machines which knit metal wires to produce something which looks somwhat like mail, usually for use on things like butchers gloves.