10 ms·
Nice! The author touches on the area properties and here's the most practical life hack derived from the standard I personally use. It uses the relationship bet
by Fiveplus 9mo ago
Nice! The author touches on the area properties and here's the most practical life hack derived from the standard I personally use. It uses the relationship between size and mass.
Because A0 is defined as having an area of exactly 1 square meter, the paper density (GSM or grams per square meter) maps directly to the weight of the sheet.
>A0 = 1 meter square.
>Standard office paper = 80 gsm
>Therefore, one sheet of A0 = 80 grams.
>Since A4 is 1/16th of an A0, a single sheet of standard A4 paper weighs 5 grams.
I rarely need to use a scale for postage. If I have a standard envelope (~5g) and 3 sheets of paper (15g), I know I'm at 20g total. It turns physical shipping logistics into simple integer arithmetic. The elegance of the metric system is that it makes the properties of materials discoverable through their definitions.
- ctxc 9mo agoTIL GSM is just g/sq m. Like duh, feel so stupid xD
- holowoodman 9mo agoIt's not you who should feel stupid. The person deciding to use nonstandard "GSM" as a unit instead of the proper "g/m²" needs to feel stupid...
- gjm11 9mo agoI'm not sure I agree. "GSM" is three syllables, versus four for "grammes per square metre". You can write it correctly using only characters everyone knows how to type quickly on their keyboard, versus either finding a way to get that superscript ² or else typing something like g/m^2 which is uglier and longer. And you can use it comfortably even if you are a complete mathematical ignoramus (you just need to know things like "larger numbers mean heavier paper" and "cheap printer paper is about 80gsm" and so forth) without the risk of turning g/m² into the nonsensical g/m2 or something. (But arguably what whoever decided on "gsm" should have done was to just use "g", with the "per square metre" left implicit.)
- cassepipe 9mo agoI beg to differ. You can totally get away with g/m2 which is not hard to type and crucially has a / to hint you what it could be about "gsm", or even more so "GSM", belongs to the reign of abbrevations and put my brain on the wrong track
- Doxin 9mo agoRoughly no one already says GSM. When talking about paper you'll hear people say things like "That's a sheet of 120 gram" GSM basically only ever appears in print. If someone DOES ask "what does 120 gram mean here?" the clarification is going to be "Oh that's grams per square meter" and not "Oh that's gee es em" I should mention GSM is also probably an americanism. I'm in the EU and out of the five packs of different kinds of art paper four are labeled in g/m2, and one has no labeled weight at all. None of them are marked in GSM as that abbreviation only works in english, while g/m2 works in all languages.
- roryirvine 9mo agoIn the UK, "gee es em" was the usual term I heard at the local paper merchants when I was a regular customer in the late 90s - early 2000s. Of the four reams of paper/card I have at home, two are labelled in "gsm", one is "g.m⁻²", and one uses both "g/m²" and "gsm" in different places. Weirdly, it seems that the specialist stuff is more likely to use "gsm" than the everyday 80 g/m² A4.
- Doxin 9mo agoI guess the fact that over here GSM was also the term for a mobile phone for the longest time has affected things some.
- KPGv2 9mo ago> The person deciding to use nonstandard "GSM" as a unit instead of the proper "g/m²" needs to feel stupid... mph, kph, cps, etc
- marcosdumay 9mo agoYeah, the people insisting on writing those are on the wrong.
- dorfsmay 9mo agoAgreed but we do have to interact with them. I once tried to sell a car with 140 Mm and got nowhere. I then changed the add to 140_000 km and got a lot more interest.
- TRiG_Ireland 9mo agoMy interdental brushes claim that the wire is 0.8 megamolar wide, which is not a normal measure of width.
- cassepipe 9mo agoI wonder if the international society of dentists keeps a standard molar in a safe somewhere
- JadeNB 9mo ago> My interdental brushes claim that the wire is 0.8 megamolar wide, which is not a normal measure of width. 0.8 megamolar = 800,000 teeth? That, uh, seems pretty wide for an interdental brush.
- astrolx 9mo ago0.8 Mmol?
- deleted 9mo ago[deleted]
- morganf 9mo ago"The person deciding to use nonstandard "GSM" as a unit instead of the proper "g/m²" needs to feel stupid..." ---> This is the sort of HN comment that I can't figure out if it's serious or a joke. I can read it in different voices and come to opposite conclusions haha
- bmicraft 9mo agoWhile we're at it, mph and the abomination that is "kph" (= km/h) even more so need to die in a fire.
- bregma 9mo agoYou mean gm⁻² ?
- holowoodman 9mo agoWell, yes. I was just too lazy to find the superscript minus ;)
- formerly_proven 9mo agoSome cursory search suggests "gsm" for grammature is confined to the US, everyone else uses g/m² or just g.
- ascorbic 9mo agoIt's gsm in the UK too
- toss1 9mo agoUmmm, not really, No. The shorthand "gsm" is a completely standard alternative in some industries. I work in advanced composites. Different weights and weaves of technical fabrics such as carbon fiber, kevlar, fiberglass, etc. are always specified in "gsm". For example, some common fabrics would be a "Carbon Fiber 3K 200gsm Twill" or a "High Modulus 12K 380gsm Carbon Fiber Plain Weave". (the "3K" and "12K" refer to the number of carbon fiber strands in each yarn in the weave, and the "Twill" and "Plain Weave" refer to the pattern in which the yarns are woven into a fabric.) I'm sure "gsm" came to be commonly used instead of the more scientific "g/m²" or "g/m^2" because no one is doing that kind of math about the materials, and it is a lot easier to type "gsm" vs either of the other two which require at least a Shift for the caret or getting out the superscript font attribute.
- bigiain 9mo agoInterestingly, sail cloth (for sail boat sails) is measured in ounces per square yard, and is just referred to by the weight with the square yard assumed - like "8oz Nylon mainsail" or "4oz ripstop spinnaker". (Or at least it used to be, my expertise here is more than 30 years out of date now.)
- thaumasiotes 9mo ago> I rarely need to use a scale for postage. If I have a standard envelope (~5g) and 3 sheets of paper (15g), I know I'm at 20g total. It turns physical shipping logistics into simple integer arithmetic. ...was using a scale for postage a concern? If you're shipping things on the order of three sheets of paper, you're way below any conceivable threshold. USPS charges a flat rate on letters under 370 grams! If you're sending 1,700 pieces of looseleaf paper in a box... just weigh the box.
- pif 9mo agoFrench "La Poste" sets the first threashold at 20 g.
- tonyedgecombe 9mo agoYou will be using Aerograms soon. https://en.wikipedia.org/wiki/Aerogram https://en.wikipedia.org/wiki/Aerogram On a related subject I just discovered that sending a letter in Denmark now costs a minimum of $4.50.
- tibordp 9mo agoGiven that we are talking about A4 papers and grams, I'd bet this wasn't in the US. In Europe, the typical flat rate is up to 100g for standard letters. And that's 20 sheets, which is not a particularly unusual letter to send.
- prmoustache 9mo agoBut 20 sheets do not fit in a regular DL or C5 envelope so you already have an hint that you may check the limits, you usually send them in a reinforced C4 enveloppe.
- tonyedgecombe 9mo ago>USPS charges a flat rate on letters under 370 grams! In the UK the limit for a letter is 100 grams: https://www.royalmail.com/sending/uk/1st-class https://www.royalmail.com/sending/uk/1st-class
- snow_flake 9mo agoOh nice, that is a neat trick! One small nitpick (that makes no difference): The side lengths of the ISO Ax formats are rounded to the next mm, so actually the A0-format has an area of 0.999949m^2
- orthoxerox 9mo agoNot to the next, to the nearest, otherwise it would have to be slightly larger than 1m^2.
- rags2riches 9mo agoThe 5 grams per sheet of common printer paper has certainly proven handy once or twice in some of my interactions in the informal economy.
- tastyfreeze 9mo agoSame for the US 5 cent coin. Defined mass of 5 grams.
- mannykannot 9mo agoDon't tell the current administration that there's something so un-American about the currency: they will insist on fixing it, and probably retire Jefferson as well.
- teachrdan 9mo agoFun fact: While the US spent more than 3 cents for every penny minted and distributed, it spends about 14 cents for every nickel minted and distributed!
- braiamp 9mo agoWhich is pennies compared to the amount of economic activity that those pennies facilitated.
- xp84 9mo ago> activity that those pennies facilitated Do you mean in the zinc mining and Coinstar? Pennies have been a bizarre ritual for years, wherein the government made zinc worth less than its pre-minted value, distributed them to banks nationwide, banks in turn to stores, stores using them once to give meaningless amounts of money to customers, customers in turn immediately throwing them on the ground or at best eventually dumping them into a coinstar, and coinstar returned those to banks. Nothing of value was going on there. I'd rather pay any zinc miners and coinstar drivers who have been displaced to play video games all day while still saving all those resources, fuel, and most of all, time.
- wolfi1 9mo agothat reminds me of an old joke: how doe the postal services make their profit? I don't get it. - Ah, that's easy. How much wieght may letters have? - 20g - And how much weight do the average letters have? - About 6g. - See? That's their profit
- pvillano 9mo agoPaper's uniform mass per area makes it useful calibrating very tiny scales. 1mm² of 80 gsm paper will weigh about 80 micrograms. "Measure the mass of an eyelash with a DIY microbalance" by Applied Science https://youtu.be/ta7nlkI5K5g https://youtu.be/ta7nlkI5K5g