Paper

Sheet of paper

Paper is a thin, flat material produced by the compression of fibers. The fibers are usually obtained from natural sources and are composed of cellulose. The most common source of these fibers is wood pulp from pulpwood trees, (largely softwoods) such as spruce. However, other vegetable fiber materials including cotton, hemp, linen, and rice may be used.

Paper plays an enormously significant role in today's world.

Paper has been and continues to be one of the most important and consequential artifacts of human civilization.

Paper has been central in the rise of literacy and development of human civilization. As a means of communicating and storing ideas, knowledge, and culture, paper has contributed to the rise in power and influence of various societies. The paper industry today is also a large source of revenue and employment for many people.

Paper is extremely important as a medium for storing and disseminating information relatively cheaply and widely. People who have learned the basic skills of reading and writing can readily access paper-based records.

Paper has been so important for the dissemination of information that, prior to the advent of the Internet and electronic publishing, it was not uncommon for totalitarian or repressive regimes to control access to paper in order to control the spread of information. If it could cut off the supply of newsprint to newspaper publishers, a regime did not need to worry about what they were publishing. Cut off the supply of office paper, and the regime didn’t need to worry that dissidents were using office copiers or mimeograph machines to copy and disseminate information about the regime’s misdeeds.

Some historians have expressed the view that paper was the key element in global cultural advancement. According to this theory, Chinese culture was less developed than the West in ancient times because bamboo, while abundant, was a clumsier writing material than papyrus. Chinese culture advanced during the Han Dynasty and subsequent centuries as a result of the invention of paper, and Europe advanced during the Renaissance based on the introduction of paper and the printing press.

Paper remained mostly a luxury item through the centuries until the advent of steam-driven paper-making machines in the nineteenth century; these machines could make paper with fibers from wood pulp. Together with the invention of the practical fountain pen and the mass-produced pencil of the same period, and in conjunction with the coming of the steam-driven rotary printing press, wood-based paper brought about a major transformation of the nineteenth-century economy, society, and cultue in industrialized countries.

Before this era, a book or newspaper was a rare luxury object, and illiteracy was the norm. With the gradual introduction of cheap paper, schoolbooks, fiction and non-fiction books and other publications, and newspapers became increasingly more available to nearly all members of an industrial society. Cheap, wood-based paper also meant that keeping personal diaries or writing letters ceased to be reserved to a privileged few. The office worker or white-collar worker was slowly born of this transformation — a change that can be considered to be a part of the industrial revolution.

Different kinds and uses of paper

At present, many different kinds of paper are manufactured, catering to a wide variety of needs. People use paper to write notes, letters, memos, and diaries; to print pictures; to perform office work; and to publish newspapers, magazines, books, and journals. For these purposes, paper is available in such forms as note paper, office paper, newsprint, and photographic paper. Most magazines use coated paper, which has a smooth, shiny surface suitable for printing pictures without dispersion of the ink.

Paper is used extensively in the fine arts, as the substrate for paintings and drawings and to make reproductions and prints. In addition, various crafts—such as the making of origami shapes and papier-mâché objects—involve the use of paper.

A number of paper products serve a variety of cleaning needs. Examples include paper towels, paper napkins, facial tissue, and toilet tissue. Paper is also used as a packaging and carrying material, such as for envelopes, paper bags, gift wrap, cardboard boxes, and some types of food wrap. Special packaging is used to protect items such as china, clothing, and perishable foods. Some paper products, such as paper cups and plates, are used mainly because of the convenience of portability and disposal.

Legal rights and responsibilities of individuals, groups, businesses, and agencies are linked to documents on paper, and people are held liable for anything they agree to by their signature on paper. For this reason, private and public contracts, titles, deeds, wills, passports, and visas are signed and stored on paper. The Fourth Amendment to the U.S. Constitution guarantees a person's rights to the security of his papers.

Local, state, and national governments record and preserve their laws, bills, and statutes by printing them on paper. Court documents are similarly recorded and preserved.

Paper plays an essential role in education. It is used for textbooks, notebooks, teacher's notes, student submissions, examinations, transcripts, diplomas, and so on. Libraries are stocked with material printed on paper, although archival material is also stored on microfilm and electronic media. To some extent, education is conducted orally and through the use of audiovisual and computer technologies, but paper continues to be used in large quantities.

Businesses, too, utilize a great deal of paper. Besides using standard office paper, businesses use large quantities of paper for business cards, advertising media, brochures, reports, bookkeeping and other accounting tasks, packaging and shipping, displays and display mounting, and so forth. The collapse of New York City's Twin Towers on September 11, 2001, after they were hit by two hijacked airliners, has been attributed largely to heat generated by the burning of huge amounts of office paper ignited by the crashes and the fuel they spilled.

Paper is important for scientific activity as well. It is used for recording, publishing, and preserving experimental data and analyses. The date or publication in a scientific journal or elsewhere—usually on paper—is generally used for establishing priority of discovery.

Life's momentous events—such as births, weddings, graduations, and deaths—are recorded, commemorated, and celebrated with the use of paper. It is considered appropriate to acknowledge and mark such events by sending and receiving paper-based cards, leading to growth of the greeting card industry. A heroic deed or achievement of a major goal is often commended on a paper document.

When trying to uncover and piece together past events, historians and others rely heavily on paper records and documents. Likewise, paper plays a crucial role in museums, archives, and other places that preserve historical records. Conversely, people shred or burn letters, documents, and other records when they want to preserve privacy, keep secrets, forestall spying, or blot out parts of history.

Paper is a medium for preserving images as well as text. Usually, photographs are printed first on photographic paper, then reproduced in magazines, newspapers, and books. The images stored on paper are frequently of equal or greater importance than words, particularly when informing future generations about past events. Examples of memorable images include the raising of the U.S. flag on Iwo Jima in World War II, and the celebrations in Paris after liberation from Nazi rule.

An especially important technological development linked to the use of paper is photocopying. Before the advent of this technology, people duplicated their documents by making "carbon copies" or by a process known as mimeographing. Today, those processes are obsolete, as photocopiers can be used to generate many copies of a document quickly, for use by students, businesses, government agencies, and so forth. This has resulted in a large increase in the consumption of paper.

Computers and electronic storage have not replaced the use of paper.

A paper trimmer

Some other important uses of paper are summarized below.

Certain types of printed paper represent monetary value. Examples include paper currency, checks, vouchers, tickets, and postage stamps.
Maps and routes or representations of terrain, waterways, and skyways are printed and preserved on paper.
Military documents and strategies are usually presented and/or stored on paper.
Architects use paper and cardboard to depict architectural drawings and construct models of proposed structures.
Engineers sometimes make paper models of proposed products, such as cars or airplanes.
When someone makes an audiovisual presentation, the person may also distribute paper copies of the images and text, to make a greater or longer-lasting impression on the audience.
Combining decorative and protective functions, paper may be used in the form of wallpaper.
Paper and cardboard are often used as building materials and in the construction of furniture.
Sandpaper is used for smoothening rough surfaces or removing coatings.
Blotting paper is used to absorb ink and other liquids.
Litmus paper is used to test the acidity or alkalinity of a solution.
In chemical and biological work, special paper is used to separate solids from liquids by the process of filtration, and to separate substances in solution by a process called paper chromatography.

<<MOVE:>>manufacturing and printing costs are relatively low, and the average user can readily afford paper and paper products.

History of paper and papermaking

Paper has a long history, beginning with the ancient Egyptians and going up to the present day. Originally most paper was handmade in sheets, but during the 19th century paper making became a large industry. The term or name ‘paper’ derives from papyrus, the material used by the ancient Egyptians, Greeks and Romans.

Further north, parchment or vellum, made of processed sheepskin or calfskin, replaced papyrus, as the papyrus plant requires subtropical conditions for growth. In China, documents were ordinarily written on bamboo, making them very heavy and awkward to transport. On occasion, silk was used, but it was normally too expensive to consider. Indeed, most of the above materials were rare and costly.

Papyrus, however, is only one of the predecessors of paper that together are known by the generic term ‘tapa’ and are mostly made from the inner bark of paper mulberry, fig and daphne trees. Tapa has been found extensively in nearly all cultures along the Equatorial belt and is made by what is possibly the oldest papermaking technique – one still practiced in some parts of the Himalayas and South East Asia. Indeed, recent archaeological excavations in China have revealed some of the oldest ‘tapa’ paper ever found which shows that paper was being produced in China before western records began. (From http://www.paperonline.org/history/3000/3000_frame.html)

If we can believe the court chronicle, in AD 105, the Chinese court official, Ts'ai Lun, invented papermaking from textile waste using rags. This can be considered to be the birth of paper as we know it today. Later, Chinese papermakers developed a number of specialties such as sized, coated and dyed paper and paper protected against ravages by insects, but they had great problems satisfying the growing demand for paper for governmental administration. They also used a new fiber-yielding plant - bamboo - which they de-fibred by cooking in lye. (From http://www.paperonline.org/history/105/105_frame.html)

Chinese papermaking techniques reached Korea at an early date and were introduced to Japan in the year 610. In these two countries, paper is still sometimes made by hand on a large scale in the old tradition. The technology was first transferred to Korea in 600 and then imported to Japan by a Buddhist priest, Dam Jing (曇徴) from Goguryeo, around 610, where fibers (called bast) from the mulberry tree were used. After further commercial trading and the defeat of the Chinese in the Battle of Talas, the invention spread to the Middle East, where it was adopted in India and subsequently in Italy in about the thirteenth century. These paper makers used hemp and linen rags as a source of fiber. The oldest known paper document in the West is the Missel of Silos from the eleventh century.

In the course of their eastern expansion, the Arabs too became acquainted with the production of paper. Paper mills were subsequently set up in Baghdad, Damascus and Cairo, and later in Morocco, Spain and Sicily. Owing to the lack of fresh fibers, the raw material used by the Arabs was made almost entirely from rags. But their defective and poorly designed processing equipment (such as breaker mills) produced a rather inferior ground pulp. By using this method with screens made of reeds, however, thin sheets were made and then ‘coated’ with starch paste. This gave Arabian paper its good writing properties and fine appearance.

Arabian-made paper, along with the secrets of its production, was soon exported to Europe, especially to Italy. From the 13th century onwards, papermakers at two early Italian centers, Fabriano and Amalfi, tried to improve the Arabian technique. Their efforts focused not on the raw material but on its preparation, and the actual papermaking process was improved. Italian papermakers developed the use of water power, the stamping mill, the mould made of wire mesh which permitted couching on felt, the screw press with slides for feeding the material into and out of the press, drying the sheets of paper on ropes, and dip sizing. (From http://www.paperonline.org/history/610/610_frame.html)

Improvements in papermaking techniques and equipment continued in Europe through the fourteenth to the nineteenth centuries. In particular, the tremendous upsurge in papermaking during the Reformation in the 16th century, coupled with the introduction of printing with movable type, soon led to a serious shortage of raw materials and to regulations governing the trade in rags. The systematic search for substitute materials met with little immediate success. Only the invention of ground wood pulp by Saxon Keller (1843) and of chemical pulp (first patented in 1854 by Mellier Watt) solved this problem. (From http://www.paperonline.org/history/17th/17th_frame.html)

Papermaking became a huge industry in the 19th and 20th centuries. These developments can be broken down into five partly overlapping periods, each marked by definite trends.

In the first stage (from about 1800 to 1860), all work sequences previously performed by hand were mechanized. This included rag preparation, the use of fillers, pulp beating, the paper machine with its various parts, and the machines required for finishing the paper (the headbox, wire section, press section, and dryer section, along with units for reeling, smoothing and packaging).

During the second stage (about 1840 to 1880), efforts were made to obtain rag substitutes on an industrial scale (ground wood pulp and chemical pulp) and appropriate industrial plants (ground wood and chemical pulp mills) were developed.

The third stage (1860 to 1950) was marked by the enlargement of the web width (i.e. width of the papermaking apparatus, permitting wider rolls of paper), an increase in working speeds, the introduction of electric drive, and further improvements to various machine parts. Machines designed specifically for the production of particular kinds of paper and grades of paper board were also developed.

The fourth stage (1950 to 1980), which was still dependent on the old methods as far as the mechanics were concerned, brought unprecedented changes in papermaking. Alongside further increases in web width and working speeds, there was the use of new materials (thermo-mechanical pulp, deinked recovered paper, new fillers, processed chemicals and dyes), new sheet forming options (e.g. by twin-wire formers), neutral sizing, greater stress on ecology (closed loops) and, most of all, automation. These changes led to specialization in certain paper types, development of new paper grades, corporate mergers, company groups with their own raw material supply and trading organizations, and closure of unprofitable operations.

The fifth stage, from 1980 on, leads into the future. The evolution of new sheet-forming principles (with fluid boundaries between paper and non-woven fabrics) and chemical pulp processes have been the main process improvements. However, the situation on the global market (increased demand, above all in the Third World, trends in chemical pulp prices, problems of location), are again raising capital intensity and encouraging the formation of big company groups with international operations. But there are also definite opportunities for smaller, local firms satisfying specific needs. (From http://www.paperonline.org/history/19_20th/19_20th_frame.html)

Steps in the process of making paper

Preparation of the fibers

The material to be used for making paper is first converted into pulp, which is a concentrated mixture of fibers suspended in liquid. The fibers are often derived from natural sources, such as softwood or hardwood trees or other plants.

To manufacture high-quality sheets of paper from plant material, it is usually necessary to break down lignin, a polymeric material that gives rigidity to the plant's cells walls. The breakdown of lignin is usually a chemical process, such as the Kraft process. This step is not needed when breaking down recycled fibers, as the lignin has already been removed from the source material. If lignin is retained in the pulp, the paper will yellow when exposed to air and light.

Alternatively, wood chips may be broken down mechanically, without using chemicals, to produce what is called "ground wood pulp." Because lignin is not removed from this pulp, yields are as high as 90–98 percent. The presence of lignin, however, causes paper to yellow. For this reason, ground wood pulp is most often used for non-permanent goods such as newspapers.

Pulp that is broken down chemically is known as "chemical pulp." The chemical pulping process breaks down the lignin and renders it soluble in a liquid (usually water), so it may be washed from the remaining fibers. Removing the lignin from wood chips also breaks them apart into the fibers that compose pulp.

It is also possible to obtain the fibers from recycled material, such as old corrugated boxes, newsprint, or mixed paper. Recycled fibers do not need to be pulped in the conventional sense. They have already been treated once, so they need a more gentle process to break the fibers apart while preserving their integrity. In fact recycling of paper and manufacturing of new paper from recycled paper products is increasing in the industrialized world today. It is possible today to buy office paper, for example, that is made from 100% recycled paper.

Once the fibers have been extracted, they may be bleached or dyed, and special ingredients may be added to alter the appearance of the final product. For example, Kaolin (calcium carbonate) is added to produce the glossy papers typically used for magazines.

Sheet formation

The pulp mixture is further diluted with water, producing a thin slurry. This dilute slurry is drained through a fine-mesh moving screen, leaving a fibrous web on the screen. A watermark, such as the mark used in paper currency, may be impressed into the paper at this stage of the process. The moving web is pressed and dried into a continuous sheet of paper.

In the mold process, a quantity of pulp is placed into a form, with a wire-mesh base, so that the fibers form a sheet and excess water drains away. Pressure may be applied to help remove additional water. The paper may then be removed from the mold, wet or dry, and processed further.

Mass-produced paper is most often made using the continuous Fourdrinier process, to form a reel or web of fibers in a thin sheet. When dried, this continuous web may be cut into rectangular sheets by slicing the web vertically and horizontally to the desired size. Standard sheet sizes are prescribed by governing bodies such as the International Organization for Standardization (ISO). In the United States, the standard size for office paper is 8 1/2 by 11 inches, and paper is usually packaged in a ream, meaning 500 sheets.

Drying

After the paper web is produced, water must be removed from it to create a usable product. This is accomplished through pressing and drying. The methods of doing so vary among the different processes used to make paper, but the principles remain the same. Pressing the sheet removes the water by force. Once the water is forced from the sheet, another absorbent material must be used to collect this water. On a paper machine, this is called a "felt" (not to be confused with the traditional meaning of felt). When making paper by hand, a blotter sheet is used.

Drying involves using air or heat to remove water from the paper sheet. In the earliest days of papermaking, paper sheets were hung up to dry like laundry. In more modern times, various forms of heated drying mechanisms are used. With paper machines, the most common drying method involves use of the steam-heated can dryer. Dryer cans heat to temperatures above 200ºF and are used in long sequences of more than 40 cans. The heat produced by this process can easily dry the paper to less than 6 percent moisture.

Preservation and permanence of paper

A big problem nowadays for libraries and archives both private and public – including archives of public records such as those of births, deaths, marriages, deeds and real estate transactions, court records, legislative actions, actions of other governmental agencies, etc. – is preservation of the paper on which these are printed or recorded. Most paper is processed with acid in its manufacture, and this acid content causes the paper to disintegrate over time. For books, photographs, and documents that are valuable or that should be preserved for other reasons, this has become a large problem.

Almost everyone has had personal experience of seeing newsprint – newspapers – with anything printed on it yellowing and disintegrating within a few years, if not more quickly. One method of preserving such newspaper pages is to copy them photographically on microfiche, microfilm or other photographic processes. Doing this preserves the materials for as long as the processed photographic film can be made to last, which can be hundreds of years if the film is processed and stored properly. In the case of photographs themselves, there has been a concerted effort to get black and white photographs processed to archival standards, which means washing the chemicals thoroughly out of the paper during the final wash steps and preserving the final photographs by storing them in acid-free boxes and/or mounting them on acid-free mounting boards. (Because of the relative impermanence of the dyes involved in creating the colors, color photographs cannot be made as permanent as black and white ones, which are based not on dyes but on highly stabile silver and silver-halide particles or molecules.)

Preservation of books in libraries has also become a big problem. If one examines books printed and bound as little as half a century ago or even less – and especially ones made during WII when because of wartime conditions the paper manufactured was of inferior quality – one sees a lot of evidence of deterioration evident in the yellowing and the crumbling of the paper. The American Library Association has attempted to forestall that by getting books to be printed only on acid-free paper. This effort has had considerable success among at least some publishers as one can frequently see notices in books, especially expensive hardbacks or other books intended to last for an extended time, saying that the book has been printed on acid-free paper that conforms to the standards of the American Library Association.

Preservation of paper-based documents has always been a big problem. Nowadays almost all kinds of documents, especially in the developed world, are increasingly being created and stored electronically as computer files, thus bypassing (at least potentially) the use of paper and the problems of paper preservation. In cases where such documents are still produced on paper, the use of acid-free paper with a high fiber content helps create a document that will resist deterioration. In theory such records stored electronically on computer-created files should be more-or-less permanent. In practice, however, these files often become obsolete or unusable even more quickly than paper ones deteriorate because computer technology and software change rapidly, and something preserved electronically today may become inaccessible in a few years because the computer hardware and software for it no longer exists.

Another problem that has arisen with computer files is the increasing use of computer voting in elections. Many people are afraid that, unless a paper record is also made and kept of each vote, computer error or outright election fraud could occur and it would be impossible to determine that this had happened if only the computer files, and no paper record, were available.

Beyond the facts about rapid changes in computer hardware and software there is the problem that gaining access to records stored in computer files requires that the one desiring access must first have access to the right kind of computer with the right software. Without such computer access, the one desiring access to the documents in question may be unable to do so. If, however, those documents were printed and stored on paper, then anyone who is able to read and understand could get access to them. There is the further problem that when a person is traveling, even though small and lightweight laptop computers have become nearly ubiquitous today, many people still find it more convenient to print out documents on paper and carry the papers with them and read them in a car, bus, train, or airplane than it is to carry a computer and attempt to use it while traveling. So there is a double edge to the question of computer versus paper storage of documents and information – there are both good and bad aspects of each.

Paper production figures

Worldwide paper production figures may not be available.

For the United States, total paper and paperboard production in 2004 at about 91.471 million tons increased 3.5% from 2003 as paperboard rose 4.0% and paper 2.9%, according to data by the American Forest & Paper Assn. (All data here from AF&PA.)

Estimated U.S. paperboard output for 2004 at 49.942 million tons compared with 48.018 million tons in 2003 and 48.126 million tons in 2002. Paper output of 41.529 million tons in 2004 compared with 40.368 million tons in 2003 and 41.561 million tons in 2002. Paper and board output in 2004 reversed four consecutive years of declining production and was the highest level in four years. Yet total 2004 output was 5.0% lower than 96.309 million tons produced in 2000 and 7.4% below the recent peak in 1999 of 98.837 million tons.

Production among major grades in 2004 compared with 2003: kraft linerboard at 22.654 million tons was up 4.3%; corrugating medium at 6.560 million tons was 7.6% higher; boxboard at 14.900 million tons was up 2.7%; uncoated free-sheet at 12.387 million tons was 1.0% higher; coated papers at 9.254 million tons was up 6.3%; packaging papers at 4.068 million tons was higher by 4.6%; and newsprint at 5.637 million tons was down 0.7%, AF&PA reported.

Total U.S. wood pulp production at an annualized rate through November at 58.936 million tons was 2.3% above a year earlier. Annualized market pulp production through 11 months was 5.5% higher to 8.835 million tons.

Consumption of recovered paper in 2004 at 35.079 million tons was 3.4% above 2003. Inventories at year-end were mixed compared with a year earlier with containerboard stocks at mills up 32.5% and at box plants up 8.7%; uncoated free-sheet down 2.3% and total printing/writing paper down 8.2%; and newsprint down 18.3%.

U.S. industry employment in paper and paper products at about 499,000 annualized through December was down 3.3% from 2003 and in pulp, paper, and board mills at 146,800 was off 2.8%. Average hourly earnings for paper and paper products employees at $17.90 annualized were up 3.3% from 2003.

2004 trade data show total U.S. pulp, paper, and board exports up 4.0% from 2003 in volume to 30.033 million tonnes and up 8.4% in value to $15.558 billion. Yet with total imports up 4.7% in volume to 25.839 million tonnes and up 11.0% in value to $19.767 billion, the U.S. pulp and paper trade deficit stood at $4.209 billion at the end of 2004. (From http://www.findarticles.com/p/articles/mi_qa3636/is_200504/ai_n13634551)

Paper in the computer age

When the personal computer was first introduced and offices were converting from typewriters and older systems of document creation and storage, there were many predictions that adoption of computers would lead to paperless offices. For the most part exactly the opposite has happened: Because it is so easy to print out copies of documents from computers, much more use of paper occurs in offices today than it did in the (now forgotten!) age of the typewriter. In fact, since it is so easy to change things on electronic computer files, it is frequently the case that a new paper copy may be printed out for nearly every change, however small. In the typewriter era that did not happen because creating a new copy for almost any change required retyping of the entire document.

The coming of the Internet too has often led to increasing use of paper. Because the Internet has made so much more information available so quickly, people are expected to look at, process, and preserve more information. This too has led to increasing use of paper to print out more and more documents.

But one aspect of the widespread use of computers and the Internet has resulted in a very diminished use of paper: The coming of email (for “electronic mail”). Nowadays in the industrialized world most people use email for either business or personal use or both, and often for Internet discussion groups and other purposes. These messages can be printed out on paper, but this is usually not done. Moreover, both personal and business use of email has led to a great diminishment in the use of paper-based written or printed mail (frequently dubbed “snail mail” because it has to travel through paper-based postal systems, which are very much slower than electronic mail). Some people have even claimed that the art of letter writing – an art that was highly developed by some people in the past and that led to publication of numerous important and interesting books that consisted mostly or even entirely of saved letters – has deteriorated and even disappeared because of email.

Some people have also predicted that this more-or-less ubiquitous and universal use of email will mean that future generations of historians and researchers will lack the documents needed to explore and understand our present-day age and culture, in the ways that historians have been able through documents to recreate and understand past civilizations, because those documents of today were never created or preserved on paper. Moreover, computer files can be deleted and permanently lost almost instantaneously with a few keystrokes on a keyboard, whereas paper files and records are more difficult to destroy. This has also become an issue in crime control and prosecution because businesses and other entities that have committed fraud and other criminal acts can quickly destroy records of those acts by deleting the email in which they were discussed. For that reason deletion of email and other computer files is now itself sometimes held to be a crime, just as destruction of paper records in order to conceal a crime is itself a crime.

Some recent developments in paper making

Paper made in the west since the industrial revolution has usually been wood based, sometimes with a fabric content, except for a few specialized papers such as those used in banknotes. However, at least one company (Cloudy Bay Cotton) has recently tried to introduce cotton-based tissue papers to Westernized countries, as an alternative to wood-based ones. Cotton-based tissue papers are less abrasive, less likely to cause allergic reactions, and far more environmentally friendly than wood-based papers, as they are made from renewable materials. The cotton fibers used for making paper are the type that are discarded as "unusable waste" by the textile industry, and they can be manufactured using fewer chemicals and less energy.

Some manufacturers, notably AMD, have started using a new, slightly more environmentally friendly alternative to expanded plastic packaging made out of paper, known commercially as "paperfoam." The packaging has very similar mechanical properties to some expanded plastic packaging but is biodegradable and can also be recycled with ordinary paper. [1]

With increasing environmental concerns about synthetic coatings (such as PFOA) and the currently higher prices of hydrocarbon based petrochemicals, there is a recent focus on zein (corn protein) as a coating for paper in high grease applications such as popcorn bags. [2]

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