To its credit, HP uses g/m� for all of its paper (laser quality, ink-jet and general purpose).
(I hope my use of Latin 9 (ISO 8859-15) encoding ensured that everyone got a superscript 2 above.) Bill Potts, CMS Roseville, CA http://metric1.org [SI Navigator] >-----Original Message----- >From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] >Behalf Of Pat Naughtin >Sent: Friday, August 29, 2003 10:42 >To: U.S. Metric Association >Subject: [USMA:26723] Re: paper weight > > >Dear David, > >I note that one of the references you quote uses the abbreviation gsm to >mean grams per square metre. > >When I investigated this some years ago, I found that paper makers also use >some other abbreviations. > >At my paper suppliers I found the following different, and incorrect, ways >to describe paper: >100gsm, 90GSM, GSM: 110 Grain:, 150GSM, 80GSM, 80GSM, 80 gsm, GSM: >140, GSM: >140 Grains:, 90 GSM, GSM: 200, 200 G.S.M, GSM: 80, 110 GSM, 100 Gm2, GSM: >150 Grain:, 80 gsm, 110 GSM, Brandname 80, Brandname 80, 80 gsm, GSM: 80 >Grains:, GSM: 150 Grains:, Gsm 90, 80GSM, GSM: 80, 80 gsm, 80 gsm, >80gsm, 80 >g/m2, GSM: 80, 80gsm, 80GSM, 80 GSM, 80 GSM, 80gsm, 80 GSM, 100 GSM, 80gsm, >80 grs/m, 80GSM, 70gsm, 80 g.s.m, 70g.s.m., 80 G.S.M, 90GSM, 90 gr/m2, 90 >gr/m2, GSM (without a number), 80gsm, 80GSM, and GM2. > >By the way, the correct unit, 'grams per square metre', measures mass >divided by area, and its internationally accepted symbol is g/m2 (that's a >superscript 2). > >Paper makers also seem to encourage the use of the jargon terms 'paper >weight' or 'grammage', which has the effect of making it difficult for >people to know that paper is described in terms of the mass of the paper >divided by its area. The correct unit g/m2 not only makes it clear what is >being measured but within the unit it also suggests how the measurement >should be done � measure the mass of the paper in grams; measure >the area of >the paper in square metres; divide the mass by the area. > >Cheers, > >Pat Naughtin LCAMS >Geelong, Australia > >Pat Naughtin is the editor of the free online newsletter, 'Metrication >matters'. You can subscribe by sending an email containing the words >subscribe Metrication matters to [EMAIL PROTECTED] >-- > > > > >on 2003-08-30 02.55, David Shatto at [EMAIL PROTECTED] wrote: > >> There seemed to be some confusion in this discussion, so I decided to do >> some research on this, and here's what I found. >> >> The official term for paper weight is "basis weight." Here's a short >> explanation from >> http://www.jhoe.com/support-downloads/paper-weight-chart.asp >> >> "Basis Weight: Basis weight is the standard measurement of an amount of >> paper. For example, the basis weight of Bond is determined by the weight >> of 500 sheets of 17"x22" paper (the parent size). If a ream of 17"x22" >> paper weighs 20 pounds, this is called 20 lb. paper." >> >> ... and here's their "paper weight conversion chart" in a >> well-organized, printable format: >> http://www.jhoe.com/images/downloads/pdf/paper_chart.PDF >> >> To make better sense of it all, here's an article called, appropriately >> enough, "Making Sense of Basis Weights." >> http://www.tappi.org/index.asp?pid=26849&bhcd2=1062174248 >> >> It includes the following interesting paragraph: >> "The rest of the world, including England, which originally blessed us >> with this system, has gone metric and uses grams per square meter as the >> standard basis weight of all types paper and paperboard. Changing to gsm >> would be a step in the right direction but old customs die hard." >> >> I found a few weight conversion tables (lb / gsm), and this site has a >> very informative page on "How to buy paper - Metric measurements" >> http://www.papercatalog.com/HowtoBuy/chapter16.htm >> >> The following paragraph from this site might be helpful for those who >> like calculating things: >> "Basic formula: To convert from basis weight in pound to grams per >> square meter, multiply the basis weight by 1406.13 and divide by the >> square inches in the base sheet. For example, to convert from 20 lb. 17" >> x 22"/500, multiply 20 lbs. by the constant 1406.13 and divide by 374 = >> 75 g/m2." >> >> David Shatto >> Los Angeles >
