International envelope Sizes / Application examples / Envelope formats / folds and sizes

 International Envelope Size  

A Selective Annotated Guide

To ensure economical mailing when materials prepared in one country are to be mailed in a second country, it is necessary to know the envelope sizes commonly used in the second country. Because designers and publishers often do not have ready access to this information, EDS Inc., Editorial & Design Se4rvices, has published this selective annotated guide to a variety of commercial, general purpose, and special-use envelopes available in Japan other, other countries using the metric system, and North America. ISO (International Organization for Standardization) envelope sizes are the official international metric envelope sizes; however, Japan uses JIS (Japan Industrial Standard) and metricated traditional envelope sizes.

N.B. The Universal Postal Union requires that envelopes for correspondence (1) measure at least 90mm x 140 mm (3 1/2 x 5 ) and no more than 120 mm x 235 mm (4 x 9 ); (2) be oblong, with the dimension of the long side being at least 1.414 times that of the short side; and (3) be made from paper weighing at least 63 gsm (grams per square meter).

In the interest of legibility, Japanese terms are not italicized in the table below.

 ISO C Series Envelopes 
This envelope series was designed to accommodate ISO A size papers; Metric measurements are the finished envelope size; Inch measurements are approximate (calculated at 25.4 mm = 1 inch and rounded off) N.B. Sizes Identified as a nonstandard do not conform to Universal Postal Union Requirements for correspondence envelopes.

* Although DL is not part of the ISO C series, it is a very widely used standard size. DL, probably at one time the abbreviation of DIN Lang (Deutsche Industries Norm, Long), is now identified as Dimension Lengthwise by ISO 269.

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 International Standard Paper Sizes 

By Markus Kuhn

Standard paper sizes like ISO A4 are today widely used all over the world. This text explains the ISO 216paper size system and the ideas behind its design.

Globalization starts with getting the details right. Inconsequent use of SI units and International Standard paper sizes is today the primary cause for US businesses failing to meet the expectations of the global economy.

 The ISO paper size concept 

In the ISO paper size system, all pages have a height-to-width ratio of square root of two (1:1,4142). This aspect ratio especially convenient for a paper size. If you put two pages with this aspect ratio next to each other, or equivalently cut one parallel to its shorter side into two equal pieces, then the resulting page will have again the same width/height ratio.

The ISO 216 paper sizes are based on the metric system. The square-root-of-two ratio does not permit both the height and width of the pages to be nicely rounded metric lengths. Therefore, the area of the pages has been defined to have round metric values. As paper is usually specified in g/m2, this simplifies calculation of the mass of a document if the format and number of pages are known.

ISO 216 defines the A series of paper sizes as follows:

For applications where the ISO A series does not provide an adequate format, the B series has been introduced to cover a wider range of paper sizes. The C series of formats has been defined for envelopes.

[The Japanese JIS P 0138-61 standard defines the same A series as ISO 216, but a slightly different B series of paper sizes, sometimes called the JIS B or JB series. JIS BO has an area of 1.5m2, such that the area of JIS B pages is the arithmetic mean of the area of the A series pages with the same and the next higher number, and not as in the ISO B series the geometric mean. For example JB3 is 364 x 515, JB4 is 257 x 364, and JB5 is 182 x 257 mm. Using the JIS B series should be avoided because it introduces additional magnification factors and is not an international standard.]

The following table shows the width and height of all ISO A and B paper formats, as well as the ISO C envelope formats. The dimensions are in   Millimeters and Inches: 

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