I learned about international paper sizes the hard way. I was fresh out of college; working for an international channel marketing firm. I was tasked with building some posters to have printed and hung in 3 offices around the globe. I had no idea each country used different paper sizes.
In addition to the US standard sizes there is an international standard known as ISO 216. It has a variety of paper series and extensions. Although this paper series is often known as the “international standard” check on the paper sizes used in that specific county.
However, the ISO standard is intriguing because it has a single aspect ratio; it’s based off the square root of 2, which is approximately 1:1.4142. This lets designers easily scale their work between paper sizes. Just as in the US paper series, each page extension is half the area of the last.
Below is a table listing the series and their extensions in millimeters and their approximate size in inches.
The A Series
The A series is of special importance because the area of A0 is exactly 1 meter squared. This series is used to calculate the GSM (grams per square meter). Remember, this measurement allows us to cross compare paper types based on thickness and weight.
The B Series
The B series is interesting because its length is various fractions of a meter; it is also the geometric mean of the A series. It is mostly used in book making, envelopes and passports.
The C Series
Is the geometric mean of series A and B. The C series is mostly used for envelopes.
In the United States, this information may seem more interesting than helpful. However, one day you may find yourself in an international role. At that point, this information is important. And, please remember to check with a print shop in country before finalizing your design.