Renewable Revolution

The international paper size standard, ISO 216, is based on the German DIN 476 standard for paper sizes. ISO paper sizes are all based on a single aspect ratio of square root of 2, or approximately 1:1.4142.


The standard defines the "A" and "B" series of paper sizes, including A4, the most commonly available size.


Successive paper sizes in the series A1, A2, A3, and so forth, are defined by halving the preceding paper size across the larger dimension. The most frequently used paper size is A4 measuring 210 by 297 millimetres (8.3 in × 11.7 in).

The significant advantage of this system is its scaling: if a sheet with an aspect ratio of √2  is divided into two equal halves parallel to its shortest sides, then the halves will again have an aspect ratio of √2. Folded brochures of any size can be made by using sheets of the next larger size, e.g. A4 sheets are folded to make A5 brochures.

The system allows scaling without compromising the aspect ratio from one size to another—as provided by office photocopiers, e.g. enlarging A4 to A3 or reducing A3 to A4. Similarly, two sheets of A4 can be scaled down and fit exactly 1 sheet without any cutoff or margins.

Weights are easy to calculate as well: a standard A4 sheet made from 80 g/m2 paper weighs 5 g (as it is one 16th of an A0 page, measuring 1 m2), allowing one to easily compute the weight—and associated postage rate—by counting the number of sheets used.

The advantages of basing a paper size upon an aspect ratio of were first noted in 1786 by the German scientist and philosopher Georg Christoph Lichtenberg.[2] Early in the 20th century, Dr Walter Porstmann turned Lichtenberg's idea into a proper system of different paper sizes. Porstmann's system was introduced as a DIN standard (DIN 476) in Germany in 1922, replacing a vast variety of other paper formats. Even today the paper sizes are called "DIN A4" (IPA: [diːn.ʔaː.fiːɐ̯]) in everyday use in Germany and Austria. The term Lichtenberg ratio has recently been proposed for this paper aspect ratio.

Agelbert NOTE: Gee what a great system! Certainly all countries but the most stubborn, nationalistic and just plain backward would embrace this celebration of logic, economic common sense (i.e. easy to figure weights for postage) and scientific leadership by the Germans, RIGHT?
 
By 1975 so many countries were using the German system that it was established as an ISO standard, as well as the official United Nations document format. By 1977 A4 was the standard letter format in 88 of 148 countries. Today the standard has been adopted by all countries in the world except the United States and Canada.

http://en.wikipedia.org/wiki/Paper_size#Other_metric_sizes

H.G. Wells said, "Human progress is more and more a race between education and catastrophe". I can't prove it but our refusal to use CFS and adopt ISO 216 is evidence pointing to who the foot dragging, backward, uneducated members of the human family hurtling us towards CATASTROPHE are.

I like ISO 216 in general and A4 in particular. How about you? Have a nice day.