The A3 paper size is one of the popular standard paper sizes used in the world. The A3 paper dimensions are part of ISO 216, which gives the specifications for the international standard for paper sizes used in many countries. The A3 size is 297 x 420 mm or 11.69 x 16.54 inches.
Aside from the North American sizes, the international standard ISO 216 is one of the popular standard sizes of paper used in many countries today. The most popular size nowadays is the A4, which is a sibling of the A3. The idea behind ISO 216 is that when you fold the paper in half it still retains its intended aspect ratio, which is square root of two.
This standard, along with the A3 paper dimensions, is based on the DIN 476 standard from Germany originating in 1922. However, an interesting side note is that the A3 paper dimensions were developed and published in France in 1798. It was published along with other formats such as the A2, B3, B4, and the B5 format during the time of the French Revolution. The sad part is that after its introduction, the said format was forgotten.
The A3 paper dimensions along with its family of paper formats did not come along all at once. In fact, the said international standard went through several steps in its developmental history. The earliest trace of its development was in October 25, 1786. Georg Christoph Lichtenberg, a German scientist, mentioned the aspect ratio of this standard in a letter he wrote to Johann Beckmann.
ISO 216 defined two types of paper sizes, which are sizes A and B. This standard, ISO 216, was published in 1975. The next format that came along is ISO 269, which was introduced a decade later. ISO 217 was defined in 1995, which also defines raw paper sizes RA and SRA, which are basically untrimmed.
ISO 216’s ancestor, DIN 476, including the A3 paper dimensions, quickly became popular in many other neighboring countries. Its surge in popularity began even before the outbreak of the Second World War. The countries that adopted it were primarily from Europe. Some of the countries that jumped in along with the popularity of the A3 paper size and its siblings included Italy, Norway, and Sweden.
The world war being fought during that time was not enough to stop this standard’s growth and eventual popularity. Countries that followed suit include Spain, Japan, Austria, and Greece. However, it was in 1977 when the A4 size overtook the A3 format in terms of popularity. However, the A3 paper dimensions are still quite comparable to other paper sizes as well.