Archives for category: Paper

In the U.S. book business when we buy paper we talk about basis weight in referring to text stock but when we move to cover stock we talk about caliper. Caliper is the thickness of a single leaf of paper. Thus a cover measured by a micrometer at 0.010 inches is referred to as 10 point cover stock (or 10pt) — a common caliper for paperback covers. We indicate basis weight by the pound sign: #. Basis weight is always the weight in pounds of a ream of paper of a standard, basis, size. Superficially pretty straightforward.

Cover and text stocks each have both caliper and basis weight, yet we never think of the basis weight of cover stock, and I found myself last week asserting that they were in fact the same. They are not.

There are two variables in that formula for figuring basis weight: the size of a ream, and the size of the standard sheet. The ream is (almost) always 500 sheets, but there are different standard sheet sizes for different types of paper.


What is the reason for these different basic sheet sizes for different print businesses? Tradition/inertia is the simple answer. When paper was made by hand, the sheet size was determined by the dimensions of the mould used by the papermaker. For example, because sheets measuring 17″ x 22″ leant themselves to cutting into four 8 ½” x 11″ sheets, this became the standard for business stationery as the papermakers serving that business made their moulds that size. Strangely we in America have never changed our units from this quaint basis.

Why do we need to know the different basis weight calculation of cover and text stock? It comes to the fore when you venture overseas for your book production. The rest of the world tends to deal in gsm (grams per square meter, sometimes written g/m2 or g/m²) a much simpler and logical, if less picturesque, system of measurement. A book manufacturer in China may well quote you cover stock referred to in basis weight terms which they’ve converted from their gsm data. (To convert from text basis weight to gsm divide the basis weight by 0.67565. For cover stock the magic number is 0.36989. You’ll no doubt need to do a little rounding to make the answer look right.) So be aware: 100# cover stock is not the same as 100# text stock. Because the area of the basis sheet of cover stock is 1806sq.ft. while the area of the basis sheet size of text stock is 3299sq.ft., your 100# cover stock would be more like a 180# text sheet — if such a thing were available. Verso has quite a useful conversion tool.

For caliper calculation, see PPI. See also Basis weight calculation.

Thanks to Steve Morehead for this link to a Princeton post about a book from their collection, the elegantly titled Die Fabrikation des Papieres aus Stroh und vielen andern Substanzen im Grossen nach zahlreichen Versuchen beschrieben und mit 160 Mustern von verschiedenen Papiersorten bewiesen, nebst einer Beschreibung der neuesten Erfindungen in der Papierfabrikation, für Fabrikanten und alle Freunde der Fortschritte in Kultur und Industrie (Cologne: Dümont-Schauberg, 1838). Having given the title I guess I’m bound to tell non-German speakers what it means: “Making paper in bulk from straw and many other substances resulting from innumerable attempts described and demonstrated by 160 samples of various types of paper, along with a description of the newest discoveries in paper manufacturing, for manufacturers and all friends of progress in culture and industry”. The book was compiled by Louis Piette (1803-62). 

Princeton’s Firestone Library tells us “The papers are chiefly from various kinds of straw (rye, wheat, barley, oats, peas, beans, lentils, and corn), singly or in combination; some mixed with hay and/or rags; and some bleached or colored. There are also five samples of cardboard made from straw and other fibers and ten non-straw papers (hay, oakum, wood, linden bark; some with rags).”

Here’s a page showing two papers made from different materials — 83: Lime bark and rags (1 part lime bark, two parts rags) and 84: Oakum).

In 1827 Mr Piette, a native of Belgium, took over the running of the paperworks at Dillingen, in the Rhineland, which had been started by his father. He seems to have gone in for long titles — he also wrote Traité de la fabrication du papier. Contenant les procédés généralement en usage pour préparer ce produit, les diverse méthodes de collage par la disolution de gélatine et dans le cylindre ou la cuve de fabrication, le blanchiment complet des chiffons, la manière de fair les papiers de couleur, et ceux de diverse subtances, descriptions détailées des machines à fair le papier d’après les nouveaux procédés, etc. If you click on that title it’ll take you to a digitized copy at Google Books — for those of you who want to read in French a 544-page history of early paper making. The Princeton University book, Die Fabrikation des Papieres aus Stroh . . ., may also be read at Google Books, though digitized images of paper samples using different substances is a rather unrewarding format if you seriously want to compare and contrast.

It must have been in the waning years of the last century that I attended a conference in San Jose and saw a presentation of an electronic book. I don’t mean anything as hi-tech as an ebook, I mean a regular book that was electronically active. By printing certain words in a metallic ink, and having connections to some sort of electronic switchboard in the spine, the book allowed the reader to access hyperlinks. To all appearances this was a normal book, but the pages were active with electrical signaling. This is not however what the paper industry would understand as action paper: action paper is a sheet impregnated or coated with inks so that it can transfer an image under guided pressure.

I used always to wonder if NCR paper’s name derived from No Carbon Required or from the company National Cash Register. Turns out it’s both. NCR the company invented this carbonless paper and rather hubristically named it no carbon required. They got a patent for this stuff in 1953. Their action paper works by having a coating of micro-encapsulated ink on the back of the sheet, and on front of subsequent sheets a layer of clay which is receptive to the ink. Pressure applied by a key strike or a pen stroke breaks the capsules of ink which react with the clay to form a permanent image. Such paper would often come in pre-assembled sets of sheets — our purchase order used to be an NCR set of three pages, top one white, second pink and third yellow. Pink would go in the book folder, and yellow in a numerical sequence — with white of course going off to the printer.

I can remember working with carbon paper until we got Xerox copiers and computers, and indeed I think I still have a box of carbon paper somewhere in this apartment. As this video points out carbon paper leaves its trace in our current life with the initials CC for a copy of an email sent to a third party: Carbon Copy. Carbon paper also finds a residual use in crafts; useful for transferring images to fabrics or other media.

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The proper handling of carbon paper was an essential skill of the mid-twentieth-century office worker. The only job in which I ever had a secretary was my very first one. A young lady would take down in shorthand the immortal words I’d dictate, and type them up with at least two sets of carbon paper to yield an original and two copies. There could be as many as four sheets of carbon paper, though the impression was so fuzzy by the time it got through to the fifth copy as to be almost illegible. We needed multiple copies because we needed one for the filing system, one for the big box of daily correspondence that circulated around the office (yes, I actually got to read all the letters my colleagues had written the previous day), and maybe one to go off to the sales rep out in the field, so he’d know what was happening. And sometimes the letter would be addressed to two people, one of whom would get a carbon copy, which of course would lead to the annotation — cc Mr X. We had to do all this carbon copying because there were as yet no copying machines in the office. If you didn’t create enough copies you’d have to type the damned document all over again, without error. Prior to inserting the paper into the typewriter there was considerable banging on the desk of the tops of the sheets of paper and interleaved carbons in order to jog them all into proper alignment. Carbons could be reused several times, but there was a limit, just as there was with typewriter ribbon.

Carbon paper was invented In 1801 by Pellegrino Turri, and was used to create the top copy on his typewriting machine. The first patent was registered by Ralph Wedgwood in 1806. The process of coating a paper carrier with a dry ink compound was analogous to the ribbon which on a typewriter would convey the top copy image: being hit by a metal shape would break the ink capsules and convey the image to the paper below. I imagine the first inks used to make carbon paper were carbon based.

Of course e-readers have accustomed us to the idea of electronic “paper”. Here, via Kathy Sandler’s Technology • Innovation • Publishing blog, comes a link to a story from New Atlas about a process for turning actual paper into an interactive surface.

The trouble with these sorts of invention is that they are just too expensive. Despite the availability of much easier to use NCR-type papers, the use of carbon paper survived for a long time in our offices. It just cost more than anyone was willing to countenance to convert all our stationery over to NCR format. Getting a hyperlink from a printed book may be fun, but most people are reading books for different rewards, and books printed on perfectly normal paper will doubtless continue to be the main medium of literary communication for a while. This doesn’t mean, as one always has to say in order to head off the digi-commentariat, that ebooks are not excellent for those situations in which an ebook is excellent.

With the western states apparently burning up altogether — well of course it can’t really be exactly like that, but there have been so many more wildfires in California and Oregon than in previous years; we’ve even seen the smoke sweeping over New York City — that we are liable to wonder if we are going to have any forests left at all. Two Sides, a paper industry site, reassures us with a post pointing out that although deforestation world wide went up in the past three decades — we lost an area equivalent to the State of Alaska — in America the opposite happened: since 1990 the USA’s afforested area has expanded by 18 million acres. This is in large part due to the efforts of the paper industry to replace every tree that they chop down, and then a bit more.

We have wildfires every year of course. As the Forest Service tells us, over the past thirty years the number of wildfires in American has been decreasing, whereas the acreage destroyed has been growing. As the climate warms up weather events become more intense: drier times become drier, there are stronger winds and more frequent lightning strikes. Also our very success in fire suppression leaves lots of fallen branches and other material in the forests to provide fuel for future burning: our western forests actually “want” to burn periodically; it’s part of their natural life cycle. Smaller more frequent fires, as in the state of nature before we arrived to interfere, lead to much less destruction. So our success in controlling fires in any given year has the paradoxical effect that next year there’s more tinder just waiting to go up. But we have no choice but to control wildfires because we have over the years allowed settlement more and more deeply into the wilds. According to an amazingly comprehensive Wikipedia page on this year’s fires, more than 6.6 million acres of forest have been destroyed already this season. Perspective however: this obviously still leaves us way ahead of the 1990’s area covered by forests.

Any increase is not due to a lack of vigilance. There are, it’s true, fewer solitaries with the superficially enviable job of sitting on top of a mountain, reading a good book, and keeping a weather eye out for lightning strikes and smoke columns. It turns out that fire lookouts have largely been replaced by airplanes in the detection of forest fires, but, as Atlas Obscura points out in a nicely illustrated story, there are still about 300 in use — down from about 5,000 in the early 20th century. The Forest Service rents out one or two of the decommissioned ones to vacationers.

Photo: Justin Franz, from Atlas Obscura

One rather positive piece of recent news was the decision of state forestry officials to recruit the knowledge of native Americans who have had a tradition of controlled burning. Getting ahead of the problem just makes sense. 

Now of course, bad as the situation in the western states is, the real big problems lie elsewhere — especially in the Amazon basin and in the Indonesian islands. See Sustain me, and Sustainable papers. Have we any hope of getting on top of these problems? Optimism is hard to sustain.

Cabbie Blog has a nice piece about war work involving the use of conkers (horse chestnuts) to create ammunition during the First World War.

Conkers is a game played by two, each with a conker threaded onto a piece of string knotted below it. You take turns striking each other’s conker until one of them breaks. The break may come when you receive a hit or when you strike your opponent’s. Disaster may result from tangled strings. Most frustrating. Various techniques of hardening your conkers were attempted: the only one I remember trying is baking them in the oven, which never seemed to do any good. But do not allow yourselves to be beguiled into the image of wartime conker battles.

Since 1889 the British Army had been using cordite to replace gunpowder in the manufacture of bullets and shells. An essential ingredient of cordite is acetone which was in short supply. In 1916 Chaim Weizmann, then a lecturer in chemistry at Manchester University, developed a method using bacteria to ferment starch, a process which yields a mixture of 3 parts acetone, 6 parts butanol and 1 part ethanol. After the War the largest plant in the world, in Peoria IL, would use molasses as raw material, but in the early years of the War, wood was the raw material you turned to for Professor Weizmann’s bug, Colostridium acetobutylicum, to chew on, other starches no doubt being needed for food! Unfortunately it was soon recognized that there were not enough trees in the whole of Great Britain to yield sufficient acetone to make enough bullets to win the war, and alternatives were sought.

Cabbie Blog tells us that school children were paid to gather conkers — something we’d all do anyway for free — though we would of course keep them for conker fights. I do recall as a schoolchild being paid to collect rosehips as part of the WWII effort to keep the population healthy, and we were given a day’s holiday every year to harvest potatoes. I suppose I would have sold conkers had there been a market, certainly my backup supply. Harvesting conkers involves the use of a big stick which you hurl up into the tree, knocking the ripe chestnuts down. You then rush to grub in the grass to get as many of them as you can grab, chucking the green shells away. It does however seem hard to imagine that there could ever have been enough chestnuts to make a difference to the war effort.

We had a great chestnut tree in our garden, and I’d try to restrict access to it as well as I could. Today I overlook a big chestnut tree in the next-door apartment complex, but for the last few years it has been showing signs of distress. The leaves have been turning brown far too early; they started browning in late July this year and the nuts are not developing remaining wizened little black balls. In the Spring we had a good show of blossoms, but most have not developed into fruit. 2017 was a problem year for this tree too, though it did better in 2018 and 2019. Is heat the problem? We seem to be evolving into a sub-tropical climate here in Manhattan. I don’t think the tree can be 100 years old yet: o tree thou art sick. Maybe the invisible worm has got it.

A rather annoying video from Vimeo:

If you don’t see a video here please click on the title of his post in order to view it in your browser.

I’m struggling to understand what message this video is meant to convey. Paper is everywhere? Everything’s made of paper? Even people? I suppose the organizers hearts are  in the right place, even if also made of cellulose fiber. I became aware of this organization, Love Paper, North America through their half-page ad in The Economist. Can’t be cheap: well, actually, maybe it isn’t too expensive. They refer in their website to “the generous donation of advertising space by sustainability-conscious newspaper and magazine publishers”, so maybe their ad was in fact free.

But how many readers will have bothered to think about this ad? Because I’m interested in paper, I did of course. But there can’t be many other Economist readers who did more than turn the page. I suppose you have to do this is a kind of industry promotion effort — we even do general book promotions from time to time.

If you go to the Love Paper, North America site you’ll learn such inspiring facts as “U.S. forest area has been increasing by over 1,200 NFL football fields every day!” Too bad nobody’s allowed to play on them during this pandemic.

In paper-consuming businesses we refer to groundwood all the time. I suspect the word doesn’t mean a whole lot to the man on the Clapham omnibus, sitting there reading the day’s newspaper.

Newsprint is the most conspicuous use for groundwood paper, though newsprint actually usually contains only about 85% groundwood fiber — depending on how much you care you’ll get more non-groundwood material mixed in to the pulp to improve its strength and staying power. When we had telephone directories and mass market paperbacks they were printed on groundwood paper too. Nowadays perhaps the commonest use in printing is in the form of coated groundwood paper: a sandwich basically of a groundwood sheet between two layers of chalky coating designed to make the sheet look good and to accept a color halftone. This type of paper is much used for magazines, catalogs and advertising. The use of  groundwood in old books can immediately be identified by the way the paper has turned a rusty-orangy-brown as the acids in it work away at the fibers. For $7.37 you can buy a pen from Amazon so you can identify whether you are dealing with acidic or non-acidic paper. (Not sure just why anyone would want to do this though. You find out because the pen draws invisibly on pH neutral or alkaline papers while showing up as an orange line on a groundwood sheet.)

The Oxford English Dictionary‘s earliest quote for ground wood (they make two words of it) comes from Forestry & Forest Products in 1885, “Ground wood was first used for paper-making about the year 1846, when it was manufactured by Keller”. Friedrich Gottlob Keller, a weaver from Hainichen in Saxony, Germany, patented the first practical wood grinding machine, which as the name might hint is fundamental to the production of groundwood pulp. Tree trunks, their bark removed, are fed into a gigantic array of rotating blades and come out the other end as little chips. This is a strangely inspiring sight: a bit like a gigantic aggressive pencil sharpener greedily consuming a whole heap of pencils with ear-splitting roaring and bellowing.

Don’t see a video here? Please click on the title this post in order to view it in your browser. (Video: Sean Doherty.)

Paradoxically, groundwood is the opposite of wood free. Wood free means not free of wood: wood free pulp is wood with the lignin removed. If you need to be reminded what lignin is please go to Wood. It’s what turns the paper brown.

J. H. Ainsworth, in his Paper: The Fifth Wonder tells us that construction paper is “a heavy groundwood paper in various colors used for elementary school art work”. He remarks that one mill made 59 colors of construction paper — his book was written in 1959, revised in 1967. You’ve all seen it; though perhaps not in 59 varieties. The bright colors favored for construction papers are due to synthetic dies added during the pulp mixing process.

But why is it called construction paper? Wikipedia tells us that it is/was also known as sugar paper (first time I heard that), and explains that usage by saying that the stout blue paper was used for sugar packaging. OKaay . . . But why did it pick up the construction name at the start of the 20th century? This is not explained. Did schoolchildren back then have to build lots of paper models while in class? I guess so: that seems to be the only available explanation, although I bet it has always been more drawn upon than cut up for models. Another of these “unimportant things” that nobody bothers to grace with a formal explanation (cf. my tortuous perfect binding investigations). The Oxford English Dictionary‘s earliest quote, from the 19 December, 1902 issue of the Decatur, IL Daily Review reads  “Baskets, sleds, and boxes made of construction paper”.

Book paper represents a very small proportion of all the paper made. It requires a good deal of care and attention to make and as such is likely less profitable than other types of paper, though some mills continue to make it because it does command a bit of a price premium.

Now we all (mostly) have to separate our garbage for recycling we are getting a bit of an education is what is and is not paper. Milk cartons are obviously made of paper, but we in New York are instructed to recycle them with our plastics, presumably because of their coatings. Coffee filters are obviously paper, but we get to recycle them with our organics, like any food impregnated wrapping paper. Those transparent inner bags in cereal or cookie packages are made of paper. I’m always torn by those padded envelopes made of plastic bubble wrap covered in manilla paper: never know which way to jump. I believe that the disinfecting wipes we waft around constantly these days are also made of paper, though the company is reticent about this, even at the website SmartLabel Products on which you can search for ingredients not listed on a package. But I’m uncertain: for every disinfecting wipe I recycle as paper, there’s one I cast one into the general garbage.

So what sorts of paper are there?

Guarro Casas lists seven types of paper:

  • printing paper
  • coated paper
  • tissue paper
  • newsprint
  • cardboard
  • paperboard
  • fine art paper

Wikipedia has a slightly different seven

  • Printing papers of wide variety.
  • Wrapping papers for the protection of goods and merchandise. This includes wax and kraft papers.
  • Writing paper suitable for stationery requirements. This includes ledger, bank, and bond paper.
  • Blotting papers containing little or no size.
  • Drawing papers usually with rough surfaces used by artists and designers, including cartridge paper.
  • Handmade papers including most decorative papers, Ingres papers, Japanese paper and tissues, all characterized by lack of grain direction.
  • Specialty papers including cigarette paper, toilet tissue, and other industrial papers.

Sandpapers, lots of building materials made from paper, that sort of blown-together packing material you meet most often in egg cartons, and so on are probably all nestling under that “other industrial papers” phrase. Wallpaper may be less popular than it once was, but where does it fit? Paper Products lists lots of different paper types. J. H. Ainsworth in his Paper: The Fifth Wonder, 3rd edition 1967, provides this amazing list of the sizes in which different types of paper are supplied:

Ever heard of safety paper? — It’s a type of paper which, if you make an alteration to something written on it, will leave a noticeable smudge or discoloration. Railroad board may have little to do with Penn Station: it is apparently a board made with a newsprint center and a panel at each side of a white or colored paper. Superficially it looks little different from Construction Paper — which is so named for what reason?

Environmental Paper shows this breakdown of paper usage, based on information from Pulp and Paper International:

Global consumption of paper

That 26% used for printing includes of course all magazines, catalogs, advertising, envelopes etc. etc. which probably represent more than ⅔ of the amount, leaving a much thinner slice for books.

Per capita paper consumption by region

Paper is consumed unevenly, as this digram from environmental shows. Clearly we in USA have a lot to recycle, so keep up the good work.

According to Wikipedia, ori means folding and kami means paper in Japanese. Origami, the art of paper folding, has they tell us been being practiced since the Edo (or Tokugawa) period, 1603–1868. Washi was the paper traditionally favored for folding. In my post about washi I told you that shi is Japanese for paper. I guess you are allowed to have more than one word for paper: but maybe there aren’t really two words. I know no Japanese, but looking at this explanation from Quora, I have to say I see the same symbol in all three words: “The word for paper in Japanese is 紙 kami. The famous Japanese paper is called 和紙 washi in contrast with the Western paper, 洋紙 youshi.” It seems that kanji symbols in Japanese are often pronounced in various ways depending on context, often with different meanings. (Go! Go! Nihon has a pretty thorough explanation.)

Notable origamist (if I’m allowed to form this word), Robert Lang, spoke on WNYC in a segment of the New Yorker Radio Hour on 30 May 2020. You can listen at this link. He referred to paper’s “memory” yet ability to take another fold despite that memory of the first. Most materials are either too stubborn to take the first fold, or too submissive to be able to remember the first while accepting the second. No doubt paper’s suitability for folding is a result of its fiber structure, with fibers tending to lie in one direction. Here’s a video of the artist at work:

Make sure your volume isn’t too high before you play this one! This next one is much less frantic and much more instructive.

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When you consider the fantastic elaboration possible in these bits of folded paper, it will come as no surprise that copyright in origami designs has become an issue. However it appears that protection is “fashious to seek”*. Japanese courts have tended to locate folding designs in the public domain, asserting that they are ideas rather than creative expression. Wikipedia‘s entry on Origami covers this.


* “The Laird o’ Cockpen”