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How can we diminish the escalation of the number of contemporary records needing preservation treatment in a short time perspective? It is this last challenge to reduce future preservation needs for paper documents that is the basis for the international work for permanent paper. It is a sad fact that organic substances will degrade sooner or later. There is, however, a significant difference when degradation is visible to the human eye after a decade or a few decades, a century, a millennium or longer periods. No paper will continue to exist without any degradation indefinitely if we have the perspective of millions of years in mind. The important difference for people needing paper as a permanent substratum for information will be the difference of papers degrading under normal storage conditions in decades or in centuries or in millennia. Rapid degradation of paper within decades or a couple of centuries is not something that we must accept as the inevitable end product of organic processes. Use of such permanent paper will be one way of delaying the degradation of future publications that will affect all organic material in the end. The word permanent should in relation to paper not be interpreted as something that will last forever, and the term ought not to be used in the sense of perennial or infinite. Permanence is the ability to remain chemically and physically stable over long periods of time. Permanent paper will therefore undergo little or no change in strength and optical properties that affect use during long term storage in libraries, archives and other protected environments. The problem of defining technical requirements for paper permanence is discussed.
In recent years, many of the paper mills have improved the storage properties of the paper. Few publishers have adopted a rational policy for using permanent paper for books that will be retained for a long period in libraries. If a book contains illustrations, it is nearly impossible for the publisher to avoid using permanent paper when it is printed in Europe. If a book only contains text, the publisher will often print the book on paper not defined as permanent according to ISO 9706.
The supply of the traditional natural fibres suitable for paper did not increase with the demand in the Western world for large quantities of paper in the 18th Century. The traditional craft of paper makers developed in the 19th Century into industrial paper production with new methods for complete defibring of the new sources of fibres, and the sizing with rosin and alum replaced animal glue or vegetable gums. The traditional papers with their good properties for long term storage became luxury items compared with less expensive acid sized papers containing mechanical pulp. These industrial papers were a mixed blessing since they became the impermanent substratum of information that should be preserved for many years to come. Some of our predecessors realized a century ago that the new papers contained internal threats against the preservation of documents. In the age before microfilming a Norwegian librarian made enquiries for copies of newspapers printed on good writing paper, but I fear that the price was prohibitive even in those days.
The concept of permanent paper is important for many people around the globe caring for the preservation of the records of humanity, and I hope you will allow me to comment shortly on my motivation for participation in this field.
When I grew up, an old book for me was normally a book from the 19th Century, and I accepted as an inevitable fact that the paper in these books was yellow and less strong compared with the white paper of contemporary books. I can still remember the first time I opened a printed book from the 15th Century. It had unfortunately been rebound in a recent binding, but the paper was still in pristine condition. My first thought was that the library had given me a modern facsimile to avoid the wear and tear of a valuable object. Careful examination, however, convinced me that this was indeed one of the oldest printed European books. Five centuries had not degraded the paper. It dawned upon me that the history of books had a curious inversion. The oldest printed books had paper appearing as if it had been made a few days ago, and more recent books were not able to keep up their appearances with the rapid changes in colour and smell of the paper.
In 1971, I was working in the manuscript department of the University Library of Oslo, then the national library of Norway. I should organize an exhibition celebrating the centennial of a Norwegian author, and I tried to find some appropriate illustrations in a satiric journal in the beginning of the 20th Century. This was an important record of Norwegian culture, but the copy of last resort in the national library was in a sad condition. These pages, six decades old, had an acid smell and broke when my cautious fingers tried to move the newsprint gently. Another task was recataloguing the letters to a major Norwegian author. His letters had been sorted four decades before into covers of acid paper made of mechanical pulp. I saw the migration effect of this modern paper on fine writing paper from the preceding century. The first and the last pages were very different compared with the rest of these precious records. The acidity had migrated into the good paper. Conservators used the term acid free paper in those days, and I asked for acid free covers for the manuscripts. We used acid free paper for the copying machines, but not for manuscript covers. After some discussion, acid free covers were introduced, but these experiences were not easy to forget and became my motivation for participation in the work for preserving the written and printed sources of human culture.
In the 80'es, librarians around the globe started many campaigns to increase the public awareness of the problems with crumbling books. Some of our European colleagues told stories about jars filled with small paper fragments falling off the shelves in the stacks. In that jar was the remains of the unknown book. No wonder some of the public expected somewhat prematurely the obliteration of the records of culture in a few years time. In Norway, I chose a slightly more humorous approach to this serious problem. We focussed on the image of Bolla the hedgehog, who is a literary personality created by the Norwegian author Alf Prøysen and designed by the Norwegian artist Hans Normann Dahl. In 1988 she emerged as the principal character in the National Office for Research and Special Libraries' campaign "No to Acid Books!" Bolla the hedgehog has every reason to fight against acid paper in books, for crumbling paper is an existential problem for her. The story about her and the other animals in a book for children was printed on acid paper: What will happen to me when the paper of my book is crumbling , she asks. Our message was this: Acid paper will crumble too fast in the passage of time. The strength of the paper will disappear, and it will not stand up to normal handling. Bolla the hedgehog and all the other wonderful personalities of world literature deserve better fates and not the annihilations in self-destructing paper.
The crumbling of paper is dependent on the storage quality provided for the paper documents. It is a slow process, but heat and humidity may speed it up. The slow degradation in temperate countries will accelerate in warmer climates. Some people will no doubt regard it as a hilarious fact that I need to spend some of my time with British documents from the Second World War. Discovering the crumbling of records of special operations from 1939 when I cautiously turned over the leaves in 1997 in the Public Record Office is not very hilarious, however. Not many records have yet reached that critical state after six decades, but slowly many other records from this period will break into small or large fragments, depressing researchers and custodians. We expect paper to preserve its strength for more than six decades, but it is perhaps not surprising that I cannot access the digital information I stored on some of the floppy disks I used a decade ago before I switched to a standard DOS-system. Information technology is developing fast, and some of the digital preservation problems will accelerate compared with the speed of paper degradation.
It is an illuminating experience to compare some of the pulp types used for modern papers under the microscope. The traditional paper fibres of paper craftsmen and the chemical pulp do not have the rugged and fragmented appearance of mechanical pulp. Understanding that the long and clean fibres give paper its strength is easy. The woods supply most of the materials for modern paper, and only a fraction of the trunk is the cellulose needed for the strong and durable paper fibres. The remaining lignin and other components of the wood can, however, also become a part of mechanical or semichemical pulps for paper. Mechanical pulp contains nearly all the wood, and substituting cheap newsprint by using pulps that are more expensive is not possible for mass distribution of information. Paper can also be recycled, but the resulting quality will depend on quality controls in the recycling process. Papers of mechanical pulp and some recycled papers constitute one end of the paper market, and there are a vast variety of paper qualities from the types that crumble fast to the papers capable of slow degradation with the best retention of strength and brightness.
I have no doubt that we all have had our experiences of fragile papers, and these experiences define two important tasks for us: Retrospectively , how can we preserve the fragile records on crumbling paper? In many countries, especially in the countries with a tropical or subtropical climate, this is a tremendous task. Looking ahead , how can we diminish the escalation of the number of contemporary records needing preservation treatment in a short time perspective? It is this last challenge to reduce future preservation needs for paper documents that is the basis for the international work for permanent paper .
It is a sad fact that organic substances will degrade sooner or later. There is, however, a significant difference when degradation is visible to the human eye after a decade or a few decades, a century, a millennium or longer periods. No paper will continue to exist without any degradation indefinitely if we have the perspective of millions of years in mind. The important difference for people needing paper as a permanent substratum for information will be the difference of papers degrading under normal storage conditions in decades or in centuries or in millennia. Rapid degradation of paper within decades or a couple of centuries is not something that we must accept as the inevitable end product of organic processes. Nature provides cellulose as the building material for the fibres that are the physical substrata for much of the information we want to preserve in libraries and archives. Nature's fibres represent a potential for both problems and their solutions. Used wisely, these fibres may last for a very long time. Unfortunately not all of nature's fibres are used wisely. The chemical composition of many papers causes too often rapid degradation. Degradation is of course the main preservation problem of paper documents from the last part of the 19th century and this century. Degradation is the cool and calculated term of paper science denoting what we otherwise call the crumbling of paper.
For a long term storage of information paper and other traditional media are still the optimum substrata compared with the relatively short time perspective of digital storage and the fast changes of information technology. Even acid sized papers normally have a longer expected lifespan than the lifespan of many digital media. Use of such permanent paper will be one way of delaying the degradation of future publications that will affect all organic material in the end. The word permanent should in relation to paper not be interpreted as something that will last forever, and the term ought not to be used in the sense of perennial or infinite. Permanence is the ability to remain chemically and physically stable over long periods of time. Permanent paper will therefore undergo little or no change in strength and optical properties that affect use during long term storage in libraries, archives and other protected environments.
Defining the technical requirements for permanent paper is difficult. The problem of making a standard for such requirements is the fact that there is no single direct test revealing paper permanence. Some experts have suggested that a standard could be based on accelerated ageing tests alone. These tests take time, and the experts are still discussing the difficulties of defining a standardized procedure that will indicate future degradation in normal storage conditions and predict the expected lifespan of a document. Nothing much happens when papers are exposed to a climate of 80 degrees Centigrade and a relative humidity of 65%. In some papers containing lignin there is little loss in paper strength after accelerated ageing in this climate, but the optical properties may at the same time be negatively affected, indicating that defining these papers as a permanent substratum for information in a long time perspective is difficult. More of the degradative changes we expect in paper in real time will manifest themselves when paper is exposed to a climate of 90 degrees Centigrade and a relative humidity of 50%.
There are so many different causes of paper degradation. The acid hydrolysis is only one of many chemical and physical degradation processes that produce crumbling paper. Neutral or alkaline sizing and some calcium carbonate added to paper will restrain the acid hydrolysis. There are, however, many other degradative processes in paper such as oxidative decomposition, cross linking reactions, changes in the structure of the cellulose, photochemical ageing reactions, physical ageing and damage by microorganisms, and you may know much more about some of these processes than I know. All these processes contributed to the effects I observed when my hands opened the yellow, withering pages of the six-decade old satiric journal. My hands did not cause the damage, but this damage was the result of the chemical process that started when they made the paper. This 20th Century paper had a low initial strength and a chemical composition that started the degradation process already in the paper machine.
Finding a single method that predicts in a short time the expected lifespan of paper for many centuries to come is difficult. We will probably have to wait for many years before this methodical problem is resolved, and we have a method calibrated with the observations of real time degradation in normal storage conditions.
Ivar Hoel's paper "Standards for permanent paper" will comment on the development of the two relevant international standards ISO 9706 for permanent paper and ISO 11108 for archival paper. Some critics want a higher kappa number in ISO 9706 to allow paper based on new high yield semichemical pulps to be included as permanent papers. An alkaline sized paper made of these pulps will degrade slower than an acid sized paper made of groundwood. The kappa number measures the tendency to become oxidized. Accepting papers that are likely to be oxidized as permanent paper may therefore be difficult. The standard has no requirements safeguarding discolouration of permanent paper. By demanding a kappa number of less than 5.0 it was not necessary to introduce a technical requirement regarding colour changes, which we have to expect in paper containing lignin. If the kappa number should be increased, new technical requirements limiting future discolouration must be considered.
I find another form of criticism against the requirements of ISO 9706 more disturbing, and it is very difficult to find any commercial interest behind this criticism. Voting on ISO 9706, some national members wanted additional requirements to safeguard paper permanence. The presence of traces of some metals in paper will serve as a catalyst for some of the degradation processes and may affect the storage properties of paper. There may be a need for defining a maximum level of traces of some metals in permanent paper. I understand this concern, and I hope that more evidence regarding such defects of the standard will be available when ISO 9706 comes up for the periodic revision ISO has instituted for all international standards.
When I signed the form authorizing the publication of ISO 9706, I hoped that the international standard for paper permanence would become a starting point to diminish the escalation of the number of contemporary records needing preservation treatment in a short time perspective. I was hoping that many books would be published on permanent paper, reducing the workload for conservators in the future. Some of these effects had already come when we were preparing ISO 9706 in close cooperation with experts from the paper trade. Many paper mills in the Western world changed the production process from acid sizing to alkaline sizing before ISO 9706 was published. In Europe, nearly every fine paper is permanent according to ISO 9706. Only one mill produces coated paper with an acid core. Many mills producing paper, containing groundwood or semichemical pulps, have switched to alkaline sizing. Thus many Western papers are permanent or have improved storage properties compared with the acid sized paper produced a few decades ago.
Does this change in the European paper trade suggest that all contemporary European books are published on permanent paper? I wish I could give an affirmative answer to this question. Few publishers have adopted a rational policy for using permanent paper for books that will be retained for a long period in libraries. If a book contains illustrations, it is nearly impossible for the publisher to avoid using permanent paper when it is printed in Europe. If a book only contains text, the publisher will often print the book on paper containing groundwood or semichemical pulps. This policy varies from country to country. In Norway publishers used to print fiction on fine paper, but nowadays they prefer to issue fiction on groundwood paper. In Denmark, on the other hand, much of the fiction is published on permanent paper. Are Danish publishers wiser than their Norwegian counterparts? A major Danish printing press has standardized its stock of paper, and a book with groundwood paper will cost more than a book with permanent paper from this printing press. Publishers getting fiction on permanent paper from this printing press cash in on standardization that benefits many of the concerned parties.
This is an important reminder for us that wise decisions are not always made only with the eyes fixed on avoiding conservation expenses in a distant future. Not all publishers have a long time perspective on the cultural importance of their business activities, but many of them have a concern for the red and black figures of their accounts. The paper mills did not switch from acid sizing to alkaline sizing to please the minority caring for the long term storage properties of paper, but this change improved the process and reduced some of the running costs of the paper machines.
A standard is not a permanent document to remain unchanged forever. Even a standard for permanent paper cannot be viewed as something permanent and not subject to any changes. The concept of permanent paper was coined by many of our colleagues who had experienced the crumbling of important documents. I think it is important that an international standard for paper permanence must be trusted by the preservation community. This is the community that sees the need of long term storage of paper documents. If the international standard for paper permanence will be changed in such a way that the preservation community no longer promotes the standard; I see no further need for such a standard. If, on the other hand, a revised standard for paper permanence incorporates new knowledge that will make it easier for us to predict the expected lifespan of paper documents in normal storage conditions, I shall be very happy to see a revised standard that commands the trust of the preservation community, and that promotes better products from the paper mills around the world.
In one European country a clever man coined the expression "the office with no paper" to express his hopes for a new, digital way of handling affairs. After a couple of years, this man became the chief executive of one of the biggest companies producing paper in his country. The consumption of paper is increasing with the new information technology. I am probably not the only person needing to print my documents in order to see what I have been writing on my keyboard. Some people try to find permanent solutions preserving all the digital information, and some of them want to print it on paper or microfilm as the copy of last resort.
Paper has been a precious commodity for two millennia. In a changing world, there is a case for preserving information on permanent paper. Not all copies of a document need to be on permanent paper. A copy on permanent paper stored in a safe environment may preserve information for a very long time. We do not need permanent paper for every document, but we need permanent paper for all the information that will become the heritage of generations to come. Permanent paper is an important concept for the long term storage of information, and a revision of the requirements for permanent paper must safeguard the long term preservation of information for the generations to come. Perhaps these generations can afford to lose the book of Bolla the hedgehog, but they should certainly not lose too much of the world literature and all the other information that will become the record of humanity.