The ISO standard paper sizes were first proposed by the German standards organization
(DIN) in the 1920's as a replacement for the vast variety of other paper formats
that had been used before, in order to make paper stocking and document reproduction
cheaper and more efficient. This A, B, C system of international standard paper
and envelope sizes were subsequently adopted by the International Standards
Organisation (ISO) in Switzerland. This paper format system is today used in
almost all countries.
See also: ISO paper sizes, ISO Series