History of Papermaking

Paper is such a commonplace of twentieth-century life that one rarely pauses to reflect that the material that makes up today's newspapers, books, prints, certificates, cups, plates, napkins, and countless other objects for dignified or humble use had its origins nearly two thousand years ago. According to tradition, this amazingly versatile material, whose importance for civilization is scarcely less than that of the wheel, was discovered in A.D. 105 by an ingenious Chinese eunuch named Ts'ai Lun. Like so many great inventors, Ts'ai Lun seized on an idea that was simplicity itself. He sought a use for the scrap cuttings of the expensive woven cloth then used for writing. He beat the scraps until they were reduced to a mass of individual fibers, mixed the mass with water, and poured it onto a cloth or bamboo screen. The water drained away leaving behind a matted sheet of fibers--paper! The basic process of making paper by spreading a slurry of fibers onto a porous screen has remained unchanged in principle down to the present, in spite of the enormous changes in the mechanics of accomplishing this act.

Ts'ai Lun's followers found that paper could also be made from bamboo, hemp, and mulberry bark. The Japanese, for example, who began making paper in the seventh century, relied primarily on mulberry bark. Even today, the Japanese "rice paper" sold in art supplies stores is made not of rice but of mulberry bark.

Conquest and caravans brought paper and the secret of its manufacture to the West via Samarkand, Baghdad, Egypt, and Morocco, and by the twelfth or thirteenth century Spain and Italy had begun making paper. The process underwent a few minor changes during this long journey, since the Chinese materials were not available, and paper was in competition with parchment as a writing material. The early European papermakers macerated cotton and linen rags for fibers, and to keep the ink of the quill pen from feathering or bleeding out into the sheet they dipped the paper into a tub of warm gelatin [an extract from the hoofs, hides, and horns of animals', which gave the paper a harder surface. This process is known as sizing. The amount of sizing in paper depends upon its eventual use. Writing paper requires a hard surface and therefore a large amount of size. Printing paper requires less, and blotting paper almost none. [p. 7]

Instead of using a bamboo screen, the Europeans fashioned their paper molds from metal wires stretched across a wooden frame, a simple device on which paper was made for all the books, drawings, and prints produced in Europe for many centuries. The skilled craftsman dipped his mold into a vat of fibers floating in water, lifted it, and by just the right series of to-and-fro motions gently formed the sheet of paper. The "vatman" was the key individual in the Papermaking business: the ability to make a uniform sheet not only once but time after time required long years of apprenticeship as well as physical endurance. After the vatman had formed each sheet, an assistant transferred it to a heavy felt, gradually building a pile of felts and paper sheets in alternation. This pile was then placed in a large press, which forced out excess water and consolidated the sheets of paper. After sizing the paper was sent to the drying loft and draped over long ropes to dry.

Since so much skilled labor was involved in papermaking, it is not surprising that the manufacturer soon began to take special pride in "branding" his paper with his own watermark in the form of his name, insignia, or a special design. The watermark is produced by a thin wire pattern attached to the screen of the paper mold. Since this design projects above the surface of the mold, the paper is thinner wherever it has touched the wire. The translucent mark is visible when the paper is held up to the light.

Gutenberg's invention of movable type in the fifteenth century firmly established the usefulness and necessity of paper. From then on the papermaker struggled to keep pace with demand and faced two ever present difficulties: the cost of labor and the scarcity of raw materials. Mechanical and chemical innovations helped to solve these difficulties but also posed new ones. Technology improved quantity at the expense of quality.

The Hollander machine, named for the country in which it was invented, was one of the most important of these innovations--a seventeenth-century version, one might say, of the modern food blender. Metal blades cutting and churning at high speed in a large tub of rag cuttings mixed with water quickly reduced even the toughest of rags to a smooth, even pulp. The Hollander soon replaced the enormous stamping machines whose heavy, pounding hammers had previously been used for pulping the rages. The sorter fibers produced by the Hollander resulted in a weaker sheet of paper but produced fifty to a hundred times more pulp than the stampers.

Another seventeenth-century innovation was the introduction of alum [aluminum sulphate], a chemical used to harden the gelatin size and to keep it from putrefying while in the tub. Alum soon became one of the standard papermaking materials, with unfortunate results for the strength [p. 8] and longevity of paper. It has been found that alum radically increases the acidity of paper. From the second half of the seventeenth century onward, use of this chemical severely diminished the strength and permanence of writing papers, and only in recent times has its destructiveness been fully recognized and corrected.

The disastrous effects of chlorine, use of which began in 1774, were realized more immediately. It was employed as a bleach for stained or colored cloth, previously deemed unusable for book and writing paper, and it caused entire stacks of paper to crumble into dust before they could even be used.

The supply of rags never seemed to catch up with the demand for paper, which by the nineteenth century had become enormous. In the latter part of that century, an ingenious papermaker in Maine, I. Augustus Stanwood, conceived the idea of "importing mummies from Egypt for the sole purpose of stripping the dried bodies of their cloth wrappings and using the material for making paper." The woven wrappings and papyrus filling were transformed into a coarse brown wrapping paper, which was eventually used by grocers for wrapping vegetables, meats, and other foodstuffs! After the ragpickers and cutters in the mill developed cholera, probably as a result of their handling infected rags, this enterprising plan was brought to an end.

The search for an economical substitute for rags long occupied papermakers. By 1800 as many as 135 substitutes had been suggested, including asbestos, thistles, potatoes, linden leaves, St. John's-wort, corn husks, cabbage stalks, and cattails. Eventually wood showed the greatest promise. Its potential as a papermaking substance had first been suggested in 1719 by the French scientist RenÚ Antoine Réaumur, who had been impressed with the ability of wasps to make paper nests from wood. In 1800 Mathias Koops published in London a book of which a part was "printed on paper made from wood alone . . . without any intermixture of rags . . . ." Koops was ahead of his time and was unable to capitalize on his invention, but within a few decades practical methods were devised for grinding and pulping wood.

The first groundwood pulp mill in the United States was founded near Stockbridge, Massachusetts, in 1867, and the very next year the first New York newspaper to use groundwood pulp was printed. Today newsprint and groundwood pulp are virtually synonymous. Anyone who has seen his old newspaper clippings disintegrate within a few years will not need to be convinced that groundwood pulp paper can be of poor quality. It is weak largely [p. 9] because its preparation produces extremely short fibers in clumps and retains a large amount of the binding material [lignin] that held the fibers together within the tree. This binding material breaks down easily into acidic components, which attack paper and cause it to deteriorate.

The wonder is that, despite the use of all these destructive agents by the papermakers, any books or works of art on paper should have survived at all. Fortunately, these materials and methods were not used uniformly by all papermakers. While some mills turned to assembly production of magazines, newspapers, and inexpensive books, other mills were less "progressive" and stayed with traditional methods, continuing to produce high-quality papers for the artist and fine printer. It thus came about that there became available a great variety of papers with widely different qualities of permanence. Today it is possible for a contemporary artist like Robert Rauschenberg to obtain paper just as fine as that used by Audubon for his Birds of America [1827-1838]. At the same time, it is equally possible for the unwary artist to use paper that will scarcely outlast an ordinary newspaper. Similarly, the art collector may find that the mat he so admired has seriously stained the picture it was supposed to protect; or the librarian may find that many recently purchased books have become unusable.

What is the lesson to be learned from these facts about paper? First, we must learn to be discriminating in our use of paper. The paper must be suited to its purpose: if performance is required, then the quality must be chosen accordingly. The traditional handmade papers of Europe and the Orient will answer the needs of special users, such as artists. For those who run today's high-speed printing presses, however, the critical technical requirements for uniform thickness and weight, special sizing, and large quantity rule out these traditional types of paper. But the papermaking industry has learned a great deal from the mistakes of the past and can now write a prescription for longevity that modern technology can administer.

The ideal combination for permanence seems to be an acid-free and alum-free pulp made of the purest possible fibers--a condition that, ironically, was essentially fulfilled by the ancient papermaking methods, although by circumstance rather than design. The purest papermaking fibers available in quantity to the modern papermaker are pure new cotton and pure high-alpha cellulose. A paper made with these fibers and without acidic ingredients may be said to be highly permanent and durable, free from the causes of internal deterioration.

To help control the external factors that effect permanence, some fine, acid-free text papers have been made with available alkali present, which acts [p. 10] as a buffer to neutralize any possible acid contamination from handling by the user or reader or from the atmosphere in which the paper is kept. Artificial aging tests carried out on paper made with pure high-alpha cellulose and alkaline additives have indicated an expected permanence in excess of three hundred years. Anyone concerned about the future of paper can now take heart, whether it is a matter of reading a favorite novel again in a few years time or of preserving a valuable picture for the next century. [p. 11]