On Fri, Jun 14, 2013 at 3:45 PM, Anna <[email protected]> wrote: > As far as I'm aware in the US paper weight is usually given in lbs > whereas the rest of the world uses gsm. >
Sadly, it is not even that simple. Not only do we in the US use non-ISO standard paper sizes, but our paper weights are also non-standard and based on the rather convoluted "basis weight". I will try to summarize my understanding, which may be flawed. In the US, paper weight is given in pounds (lbs), but that number is the weight in pounds of 500 (or 480 or 1000, depending) sheets of the paper in the basic sheet size of paper of that type (which varies for different types of paper). So, on the shelf at the local office supply store you might see letter sized (8.5x11 inch) bond/printer paper (roughly equivalent to A4) that is 20lbs. That means that 500 sheets of that same paper in sheets that are 17x22 inches (uncut size for that paper type) would weigh 20lbs. http://en.wikipedia.org/wiki/Paper_density GSM is much more sensible, but is not well known outside of specialty paper stores. Most people in the US are generally unaware of paper standards outside of the traditional sizes used here. They are also unaware of what the various paper weights actually mean. At best, they can recognize the weights of the few papers they actually use from time to time (e.g. bond/printer paper and cardstock). I hope that makes sense. malachi
