Paper Sizes and Weights:
U.S. vs. the World?

Much of the world has gone metric--except North America. According to Wikipedia, "As of 2006, 95% of the world's population live in metricated countries."

In the graphic arts, this affects print production because of paper sizes and weights. Here in the U.S., we use inches and pounds for measuring and weighing paper.

If this world is indeed flat, and printers and print customers are doing business globally, they need to know something about standard paper sizes and weights.

Oy! Help!

Many of my Print Tips subscribers are in the U.K., and a query from one such reader led me down this interesting paper trail.

"When you refer to weights of paper in lb or pt it means absolutely nothing to me. I have never come across this measurement system in the UK. Would it be possible to give an equivalent in gsm?" he wrote.

It gnawed at me. Having a soft spot in my heart for all things British, I dug into the research like a dog on a bone. I figured that many graphic arts professionals would benefit from this information--myself included.

I hit the jackpot.

Ten years ago, a young German student named Markus Gunther Kuhn wrote a detailed paper on international paper standards while earning a master's degree at Purdue University (Indiana, U.S.). He was a Fulbright Scholar there.

Mr. Kuhn holds several degrees, including a Ph.D. from the University of Cambridge in England. Today, he is a Lecturer at that University's Computer Laboratory and a fellow at Wolfson College.

I contacted Mr. Kuhn by email to ask if his report is current. He replied that, to his knowledge, nothing has substantially changed since 1996, when he began this 'paper on paper.' He occasionally adds to it.

"International Paper Sizes"

Mr. Kuhn's paper covers this topic in wonderful detail. Save it on your desktop if you are involved with printing and paper buying. (or print it off; it's 23 pages.) I have no idea if the paper is totally accurate. All I know is that it is the best online resource about international paper sizes and standards that I've come across.

Having read Mr. Kuhn's paper, I want to share a few meaningful points:

• The international standard for paper size is ISO 216. ISO stands for the International Organization for Standardization. ISO comprises representatives from around the world; they produce industrial and commercial standards. ISO paper sizes are based on the metric system.

• The U.S. and Canada are the only countries who have not adopted the ISO paper standards.

• Among the ISO paper size standards, A4 is the most important one, as it's most commonly used.

• A and B are the common paper formats in the ISO standards. The C series is for envelopes. They are, of course, measured in millimeters. (Note: Kuhn writes that no international standards exist yet for window envelopes.)

• Grammage is a term you should know. It means "grams per square meter" and is abbreviated as "gsm." (I am wondering how one pronounces it. Does it rhyme with fromage? Oui? Non?)

• In the U.S., paper is measured in inches. Many of the sheets produced for commercial printing presses are multiples of 8 1/2 x 11".

• In the U.S., paper weight is based on a particular sheet's basis weight. Basis weight is figured out by using one ream (500 sheets) of a particular sheet of paper at its basic size (i.e., 17 x 22", 20 x 26", 25 x 38") -- which is the uncut size. It is very confusing. Uncut basis sizes vary from paper to paper. (A great explanation on this topic can be found in the book "Getting It Printed" by Eric Kenly and Mark Beach. Search on Amazon for it and buy it straight-away.)

Markus Kuhn gives us several helpful charts, including one that shows the width and height of all ISO A and B paper formats. If you print out his paper, this chart's on page 3.

If you work outside of the U.S., don't miss his table on page 16, where he shows ISO paper sizes in inches.

To access Markus Kuhn's paper, go to this link: www.cl.cam.ac.uk.

For a conversion table of U.S. paper weights to grammage, go to http://home.inter.net/eds/paper/grammage.html. (Again, I do not know if this information is accurate.)

In print buying, details are everything. Armed with this information about international standards for paper sizes, every buying professional will be a little bit more informed.

Your comments, thoughts, and insights about this topic are of particular interest to me, so please get in touch.