Paper Size and Quality

There are basically two systems in use today: the international standard (A4 and its siblings), and the North American sizes.

The largest standard size, A0, has a surface area of 1m². A1 is formed by cutting a piece of A0 in half, retaining the aspect ratio. A4 then, is 1/16 of 1m².

There is also the less common B series, which are the geometric mean of successive A series sheets. The C series, used only for envelopes, is half way between the A and B series of the same number. An example of the practical usage of this, is that a letter written on A4 fits inside a C4 envelope. The main exception to this rule is DL, which is designed take an A4 letter folded into three.

download paper-size chart