stix Posted June 6, 2016 Share Posted June 6, 2016 I'm going to be rolling some small spolettes and making a small can shell (45mm OD - 1.75"). I'll be using 65gsm virgin kraft. There doesn't seem to be a simple conversion that I can relate to. In the US, what average # (lb) weight is your standard "Laser Copy Paper"? - In Oz., we use 80gsm (grams per square meter). Link to comment Share on other sites More sharing options...
marks265 Posted June 6, 2016 Share Posted June 6, 2016 Is this what you're looking for to help you? Mark Link to comment Share on other sites More sharing options...
stix Posted June 6, 2016 Author Share Posted June 6, 2016 Thanks Mark, appreciated, but No - It doesn't help - it gives two answers.?? Link to comment Share on other sites More sharing options...
Mixer Posted June 6, 2016 Share Posted June 6, 2016 (edited) 20lb is the average = 30 gsm. I`m not sure if you are looking for overall thickness, strength, or both. Obviously, the differing paper thickness has no bearing on relative paper strength. Edited June 6, 2016 by Mixer Link to comment Share on other sites More sharing options...
stix Posted June 6, 2016 Author Share Posted June 6, 2016 20lb is the average = 30 gsm. I`m not sure if you are looking for overall thickness, strength, or both. Obviously, the differing paper thickness has no bearing on relative paper strength. So 40# is around 60gsm. Thanks Mixer, that's what I was after. Yep, accepted that the thickness has no bearing on the strength.eg. cartridge/blotting paper is a good example. It's 'bulky and thick', but you wouldn't use it roll a spolette. Link to comment Share on other sites More sharing options...
Mumbles Posted June 6, 2016 Share Posted June 6, 2016 The answer to this is always going to be a little bit complicated. The poundage rating is weight per ream. That will depend on number of sheets in said ream, density of the paper, and how large the sheets are. I know this seems weird and arbitrary now, but it dates back to when paper was hand made. Paper designed for writing (8 1/2" x 11") would be more convenient to be a different size than paper designed for book bonding, and making newspapers, etc. Certain things would be made with a finer grain or fibers, which made the paper smoother and more appealing as well. Kraft for rolling cases is wrapping grade or newsprint grade. The conversion is 1 lbs newsprint = 1.6267 gsm 1 Link to comment Share on other sites More sharing options...
stix Posted June 7, 2016 Author Share Posted June 7, 2016 Perfect! Thanks Mumbles - the whole thing was driving me mad. I looked at a few tables on google and they seem to suggest that 40# paper can vary depending on it's use, ie. Book cover, text, tabs etc... Utter madness!! Now all I have to do is simply multiply the given pound (#) weight by 1.63. Most of the time it will be good enough for my current purposes. As an aside, does anyone know why the # symbol is used to denote weight, as opposed to pounds (lb) - Is it just for paper? The ultimate irony is that I work at a printing company. Although in the pre-press department, I do have a good feel of various paper weights (metric system) but it didn't help me with this. Link to comment Share on other sites More sharing options...
Mumbles Posted June 7, 2016 Share Posted June 7, 2016 I was intrigued by your question as well. I found two alternate explanations. The first seems more prevalent, and probably some underlying reason for the second, if true. We could just go back to calling it the octothorpe. http://www.newyorker.com/books/page-turner/the-ancient-roots-of-punctuationhttps://www.quora.com/Why-has-the-symbol-been-called-a-number-sign-pound-sign-and-now-hashtag Link to comment Share on other sites More sharing options...
stix Posted June 7, 2016 Author Share Posted June 7, 2016 I love it! "Octothorpe" sounds like a fictitious name that my brothers and I (at about 10yrs old) would have come up with to describe some sort of alien race or machinery, ie. Tom Swift books etc. I read through the links, interesting reading. The fact that I learned something seemingly obscure, yet relevant, is testament to what I've always said about this forum. You never know what you might learn. Link to comment Share on other sites More sharing options...
otto Posted June 7, 2016 Share Posted June 7, 2016 Love the link to ancient roots! Another container to add to my "Warehouse of Useless Knowledge" (which I happen to be quite proud). Lloyd should get a kick out of it as well. Octothorpe.... I'll be using that. I also happen to be a "Libra". Does that mean I'm a pound or I should be pounded? Back on topic. Using Mixers ratio, if you go to the calculator in the link it returns 29.6 gsm for 20# of text grade or 59.2 for 40# so the text conversion is close to that. I'm no expert but based on Mumbles contribution there is at least a third grade (newsprint) that has another ratio. For future use (if it were me) I'd build a Q&D calculator in excel..... I've done that for ball mill jar volumes, BP parts based on how much I want to make, a circle calc for landscape bricks, well, all kinds of stuff. /m Link to comment Share on other sites More sharing options...
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