Paper


Paper and ink are writing materials of great antiquity, originating in Egypt. Paper has many other uses than as a writing or printing material--it can be used as a wrapping, for filtering, for decorative and artistic purposes, or even as an engineering material. Paper is now available at very low cost and very high quality, a uniform and attractive product. It makes up a large part of household waste, mainly as packaging and as advertisements in the newspaper. This cheapness and ubiquity conceals paper's great effect on society and interest in history.

Paper is strictly defined as a felt of cellulose fibres, usually with adhesive components and fillers. The source of the fibres is normally ground wood, digested with lye and other materials to remove unwanted components of the wood, treated with sulphite to bleach it. Unless the acid chemicals are thoroughly eliminated, they cause the paper to oxidize and disintegrate in a relatively brief time. The source of the fibre was originally cotton and linen rags, or perhaps straw, which did not require the sulphite treatment, and so made a much more permanent paper. The wood fibre process was developed around 1840, and chemically-digested wood fibres in 1851. Papers made before that are all rag papers of good permanence, but later papers may disintegrate rapidly, as seen in newspapers and magazines, which used the sulphite paper for economy.

Pure paper is porous, and water-based inks cannot be used with it, as can easily be seen by writing on a newspaper with a fountain pen. For printing purposes, oil-based, viscous inks were developed, which were one of the elements making printing possible. Water-based ink is made from soot and water, with an adhesive agent. It was used in Egypt, as well as in China later, and is now called India ink. Oil-based ink was originally made from soot and linseed oil. It would not wick in paper, stayed in place on metal type, and kept the paper from moving during printing. Printing inks are thick and viscous, applied with a spatula. Paper can be written upon with a pencil, and must have the necessary roughness to rub off the graphite. Writing paper is sized with kaolin, china clay and given a shiny, hard finish. In fact, this is the largest use of white china clay. Making good writing paper requires careful technique.

If paper is defined as a writing material in the form of sheets made from cellulose, then papyrus must also be included. This was the Egyptian paper, used in the classical world until the fourth century as the material for books and permanent records. It was a very satisfactory product, something that has recently been recognized upon the discovery of papyrus that was not in an advanced state of weathering. Papyrus was white and flexible, took water-based ink well, and was relatively permanent. It was made in rather small sheets, perhaps 5" x 9" to 9" x 15" in size, like modern typing paper. The finished sheets were glued end-to-end and stored as rolls. They could also be stacked up as codexes, but this was not as convenient because of the difficulty of binding small individual sheets, so as long as papyrus was used, rolls were common. The common word "volume" for a book comes from this practice, since it refers to something rolled.

Papyrus comes from the pith of the papyrus reed, Cyperus papyrus, which grows up to 20 ft high in Egypt. The pith was sliced into thin strips, which were stacked horizontally and vertically and moistened. A pile of such sheets, separated by felt sheets, was then subjected to great pressure in a press. The sheets were then separated and dried, and were ready for use.

For less permanent writing, wax tablets were used in the ancient world. They were easily written upon with a stylus, and just as easily erased by smoothing them. The typical wax tablets were in wooden frames, hinged together with leather so that they could be closed and protected. This was the diploma, a word still used for something different. Parchment or vellum was another writing material, made from the sheet of connective tissue of the skin of calves or sheep. It was a good writing material for water-based inks and quite permanent, but was very expensive. Its use grew when papyrus became difficult to obtain from Egypt and disorder decreased public literacy in the West during the fourth century. Since it was available in larger sheets, the sheets could be folded to make book pages, and the folded sheets bound by sewing. This made codexes much more practical, and they gradually replaced rolls. With a codex, you have immediate access to any part of a book without having to unroll it. From the fourth century to the invention of printing, paper was not much used in Western Europe.

Paper from felted cellulose fibres (mulberry-tree bark) was invented in China around 100 CE, and we have examples from 150 CE. This satisfied a long-felt need for a better and cheaper writing material. It spread to Japan around 610 CE and into Central Asia around 750 CE. Marauding Arabs found Chinese paper when they invaded Samarkand, and liked it so much they spread it as far as Spain by 1150, when the first paper mill was established in Europe there. The introduction of movable type in the mid-15th century greatly increased the demand for paper, since by its uniformity and properties it was well-suited to printing. Paper-making became the first example of domestic recycling, since it used discarded rags as its raw material.

Paper is readily made by hand. The fibers must first be separated and dispersed in water, by pounding, slicing and tearing, a fairly difficult but essential process. A mould is then prepared with a screen of metal wires, like a sieve, which is held in a wooden "deckle." The original Chinese process used the ever-useful bamboo for this. It is then raised through an even layer of fibers, with sizing materials and fillers, floating on the surface of water. The delicate felted sheet produced when the felt has dried somewhat is then stacked with others with separators, and firmly pressed, like papyrus. The wires may be arranged in a square pattern, like a screen, or close-spaced wires in one direction may be bound with fewer transverse thin wires. The pattern of the mould is left on the paper; the former gives a "wove" pattern, the latter a "laid" pattern. These terms are still used for machine-made papers. A design of wires in the mould leaves its trace in a watermark, also still frequently seen. Handmade paper comes in individual sheets, which can be relatively large.

Henry and Sealy Fourdrinier of London improved a continuous paper-making machine of Roberts in 1803. This machine-made paper was much cheaper than hand-made, and came in large rolls that made improved printing presses possible. The demand for rags exceeded the supply, stimulating the search for other sources of fibre, which was satisfied by ground wood, as mentioned above.

Four sheets of hand-made paper were folded to make 8 leaves; this was called a quire from Latin quaterni, "by fours." Another name for this was a quaternion, later used by Hamilton for his hypercomplex numbers. These quires could then be sewn for binding. Later, a quire came to mean 24 sheets of paper, which it usually does today. Twenty quires, 480 sheets, was called a ream. This word came from Arabic rizmah, a bundle, by a devious route. A ream was often 500 sheets, to allow for imperfections, and today a ream is usually 500 sheets. A ream of drawing or handmade paper may be only 472 sheets, for some reason.

In the United States, typing paper was often furnished in 17" x 22" size, called "medium drawing paper." Until recently, offices received their paper in this size, which was most economical. It was cut into fourths by a stout guillotine, and wrapped for distribution. These "quarto" sheets were 8-1/2" x 11", the standard U.S. size for typing paper. Paper for legal offices and court documents was 8-1/2" x 14" for some reason. To add to the variety, military paper was 8" x 10", a rather good size that was the common English size of typing paper before metrication.

International paper sizes were established by the ISO on the basis of the earlier DIN specifications. These standards are used world-wide except in the United States and Canada, and in some cases in Japan. The fundamental size, A0, is 1189 x 841 mm, which is 1 m2 in area. Folded in half, each half is A1, 841 x 594. This is repeated for A2, 594 x 420, and so on. A3 is 420 x 297, A4, the commonest size of typing paper is 297 x 210, about 8-1/4" x 11-3/4". A5 is 210 x 148, A6 148 x 105, close to the old 12mo size, A7 105 x 74, A8 74 x 52, A9 52 x 37, and finally A10, 37 x 26, only about 1-1/2" x 1". The ratio of width to height in each case is 1:1.4142. This ratio for the U.S. typing papers is 1.294 and 1.400, so legal paper has about the same proportions as A4. 8 x 10 has the smaller ratio 1.250. All of these ratios are considerably less than the golden section ratio of 1.618. In the United States, some papers, mainly for technical and artistic purposes, are based on a 9 x 12 size.

The weight of the paper is specified as the weight of a ream of 17" x 22" paper in the U.S., and by g/m2 in international specifications (the weight of an A0 sheet). A typical typing paper is 20 lb, or 75 g/m2. A heavier paper is 24 lb, or 90 g/m2. Paper is so uniform that small areas of it can be used for small weights. A square centimetre of 75 g paper weighs 7.5 mg.

When paper was only available in sheets, books were printed on whole sheets that were then folded and bound, and finally cut on three sides to make the finished book. Until well into the 19th century, the fly side opposite the spine was left uncut, and the purchaser slit the pages. This effectively prevented a bookshop from becoming a library, a common complaint of merchants today. I would like to know the details of printing and folding for this process, which must have been quite intricate.

The book was called quarto (Latin: "by fourths") if the sheet was folded once horizontally and once vertically, abbreviated 4o. If each sheet made 8 pages, the book was octavo, abbreviated 8vo. If each sheet represented 12 pages, the book was duodecimo, abbreviated 12mo. Starting from a 17 x 22 sheet, a 12mo would be 4-1/4" x 6-3/4" and wind up 4" x 6-1/2" after trimming. I have determined this by measuring a book called 12mo printed in 1888. The finished size of an 8vo book seems to be 5-1/4" x 8". It is quite obvious by looking at books that they are no longer standard sizes, so these terms would not have constant meanings. They may, however, provide colorful descriptions, and it is good to know roughly what they meant. In international sizes, A6 is roughly 12mo, A5 8vo, and A4 4o.

The References give some examples of interesting things to do with paper. There are, of course, many more, including the art of Origami. When I was very young, wartime shortages eliminated the use of metal in toys, and paper, and its relative cardboard, was substituted. These were excellent toys, inexpensive but well-made, that you assembled from parts punched out from a die-cut page. I have such good memories of these that I would like to see them again, but they have irreparably sunk into oblivion. All we have left is plastic, which makes excellent kits, but is not the same thing.

References

T. K. Derry and T. I. Williams, A Short History of Technology (London: Oxford University Press, 1960). See Index of Subjects.

Funk and Wagnalls New Encyclopedia (New York: Funk and Wagnalls, 1979). V. 18, Art. Paper.

T. S. Row, Geometric Exercises in Paper Folding (New York: Dover, 1966).

J. S. Rudolph, Make Your Own Working Paper Clock (New York: Harper and Row, 1983).


Return to Tech Index

Composed by J. B. Calvert
Created 21 July 2003
Last revised