The word Chainmail is actually an anachronism. In the Middle Ages and Renaissance, it was simply called "mail", "maile" or "maille".
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, rings are often just butted together, forming chainmail unsuitable to actual combat use.
In tests during the World War I, chainmail was tested as a material for [bullet proof vest]?s, 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.