The Abbey Newsletter

Volume 18, Number 3
Jul 1994

Lignin on Trial:

A Report of the ISR Workshop
July 6-8 at ASTM Headquarters

by Ellen McCrady

The debate over whether lignin affects paper permanence ("ISO Responds to Claim that Lignin is Harmless," AN, Dec. 1992; and Alan Bird's July 1992 letter to the editor) has gained momentum and taken shape in the last couple of years. The Commission on Preservation and Access recently gave top research priority to the effect of lignin on paper permanence (December 1993, p. 108). And the Institute for Standards Research (ISR), a subsidiary of the standards organization ASTM, held a workshop in Philadelphia July 6-8, to start planning permanence research to settle the debate.

It was a blue-ribbon group. Thirteen of the 15 speakers on the first day had PhDs, and the 100 or so who stayed for the small-group discussions on the second and third days represented major industrial, governmental, independent and collection-holding organizations from around the world that have a stake in the outcome. Many of them were researchers themselves, and could have given first-rate papers of their own. They came from 12 countries besides the United States.

ASTM (American Society for Testing and Materials) has a lot of experience eliciting consensus from groups that include opposing interests. It is a world-wide standards-setting organization, and it always invites all interested parties to take part in the process, as long as commercial or industrial representatives do not outnumber the others. Its subsidiary, ISR, was set up six years ago to facilitate research on which to base the standards committees' decisions. ISR offers administrative support, not only as a facilitator, but as a fund-raiser.

Background for the Workshop

The initiative for this meeting, and for the whole project, came largely from Canadian pulp mills that make CTMP, a new type of high-yield pulp; but other pulp producers are interested too. Some of them advocate CTMP as a more environmentally-friendly pulp than bleached kraft, though this is debatable.

A new subcommittee, D 6.50 on Paper and Paper Products Composition, was set up last year in ASTM by the pulping interests, to explore ways of formulating permanence standards based not on the composition of the paper (i.e., the pH, lignin, and calcium carbonate as specified in all modern standards) but on the performance of the paper. (Since we cannot wait three to five hundred years to measure actual performance, it will likely be necessary to use an accelerated aging procedure to serve as a proxy for future performance.) Like other ASTM committees, D 6.50 has a balanced membership. This workshop was one of the steps in the program of that committee.

The expenses of the workshop, and the planning meetings that preceded it, were borne by 20 sponsors, which included 12 paper industry companies and eight cultural institutions or governmental agencies. The sponsors also planned the workshop. A new set of sponsors will be solicited for the research program. No one can say for sure yet how much money the new group of sponsors will be asked to supply, but two figures that have been mentioned are two and three million dollars.

All those present at the workshop welcomed the prospect of new research on permanence and accelerated aging. For the last few decades, the need for research has built up more quickly than the few active labs could respond to it. Furthermore, industry has been doing its permanence-related research largely in isolation from the collection-holding institutions. That isolation has now been broken, and new possibilities have opened up. Several participants mentioned the historical importance of this occasion. What made it historical was simply the fact that it happened, because while the group set priorities, it did not make any decisions. The purpose of this meeting was to provide a forum for the broadest possible input into the requirements of a research program.

Industry Research & Conservation Research

Although a few individuals in the paper industry have done permanence-related research, sometimes in collaboration with conservation scientists, the industry itself does not have a continuing tradition of investigation on this matter. Until the last year or two, few industrial researchers were aware of permanence research by library and conservation scientists. In fact, one of the industry people present was still referring to this body of research as "anecdotal evidence" even after hearing the conservation scientists' papers. He was not typical. Several of the industry scientists expressed interest in doing research on historical papers, as William J. Barrow, Helen Burgess and others have done.

People from the two research communities swapped references to major abstract journals and databases in both fields, and one industry researcher had kind words to say about Restaurator, which he had discovered in the library. (This international journal, established in the 1960s, publishes original research on book and paper conservation.) John Waterhouse of the Institute for Paper Science and Technology said that the IPST Abstract Bulletin has been abstracting literature on recycling and will now cover permanence.

Some attendees who were unfamiliar with the fields of permanence research and conservation couldn't understand what all the discussion was about. Twice they tried to settle debate by saying, "You tell us what you want, and we'll make it for you." Others were afraid of unfair demands from the "cultural community" and of costly changes in their papermaking methods, like those changes resulting from environmentalists' demands for recycled and chlorine-free paper. They described the massive scale on which the mills produce printing and writing paper, and doubted that their entire output needed to be permanent, since only a tiny fraction of it would be kept for a long time. (One asked, "Do we treat all the tonnage from a mill as permanent?" and another wanted to know why 1% of the purchasers should dictate to the other 99%.)

Repeatedly the discussion came back to the question of whether it was possible to identify ahead of time those copies of books and documents intended to be retained indefinitely, so that they, and they alone, could be put onto permanent paper. I described how this idea was given a good try in the 1930s or thereabouts, with "library editions" of books and rag paper editions of the New York Times, and how it was abandoned when the advantages were seen to be outweighed by the costs. Karen Garlick, a conservator formerly with the National Archives, said that the creators of documents in archives are frequently unaware that the documents will be appraised 30 years later for permanent retention; the 60,000 cubic feet of records that the National Archives takes in each year, she said, make up less than 1% of the documents created by the government. Somebody else drew a parallel with airbags: We have them in our cars, he said, and we like to have them there all the time, though we very seldom use them. Another said, "Good paper should be cheap and ubiquitous."

There were other questions that were asked, and answered, or not answered, and asked again. (Our discussions in both the large group and the small groups were orderly but disjointed, because of a ground rule established by the facilitators to guarantee that only one person spoke at a time: you could not speak unless you were holding "the stick," which was actually a felt-tip marker. By the time your turn came, other topics had been raised and your context had evaporated. The stick method did, however, prevent arguments and promote listening.)

Questions that kept coming up were: What is permanence? Does it mean a lifetime of 50 years? or 1000? or what? Should each grade (kind) of paper have its own permanence standard? Should a standard have one level of permanence, or two or more? (One comment on this subject was that Sweden had had four classes of permanence in its 1907 standard; administrators were relieved when they were replaced by a single class in the 1964 standard.)

Other questions were: How many kinds of permanence are there, really? (The industry leaned toward mechanical and optical, omitting chemical permanence or stability.) And: How can you tell when a paper has reached the end of its life? (Embrittlement is the big factor here, but how important is yellowing? Some people said yellowing of books and documents is not objectionable, as long as you can read the text, but a framer present said that the pages of books are often framed as works of art. For these books, it is objectionable. Light is a major cause of deterioration in framed objects, and changes in their appearance are taken seriously. Another point made was that microfilming of paper darkened by aging is more expensive, because the cameras are not easily adjusted for different exposures.)

Who is the end user? What does the end user want? These questions were not simple to answer. Papermakers usually see as their end user the printer or other customer who runs paper through a machine. In the context of permanence, however, the end user is a long way down the line. Participants from the conservation community contributed these comments:

There was a question or two on the permanence of recycled paper, but no answers or comments were offered.


The biggest disagreement, of course, concerned the effect of lignin. Canadian industrial research has yielded results that amazed the participants from the art, library and archival world. These were some of the pro-lignin statements made:

  1. Lignin has no effect on permanence, even at a pH below 5.
  2. Lignin-containing paper is stable to pollutants.
  3. Ozone increases fiber bonding of mechanical pulp, but lignin-free paper is degraded by ozone.
  4. Lignin is an antioxidant that protects cellulose.

One rather mild comment summed up the reactions of those familiar with real-life paper in collections: "It is surprising to hear about such beneficial effects of lignin. Surveys in the Netherlands and other countries show that groundwood is unstable."

These two points of view can only be reconciled by research, which will come later.

Another disagreement concerned the type of standard that would result, and whether it would depend on accelerated aging tests. A speaker from Germany had been invited to come and describe the German paper permanence standard, DIN 6738, which was approved two years ago. This standard relies on accelerated aging. It was written by some (not all) paper companies, and was approved by DIN, but not until after all librarians and archivists had resigned from the committee in protest, or had their membership cancelled by DIN. The speaker did not acknowledge this, but spoke as if all parties had participated in writing the standard. Several people asked him about whether the cultural community had accepted it, and what had been done to persuade them that it was a good idea. He dodged every question. Finally someone in the audience said that it wasn't sold to the librarians. In reply to another question, the speaker admitted that no users were known to have tested any papers for conformity to the standard.

This importance of testing by consumers was not gone into at any length. Most participants perceived a permanence standard as something that manufacturers conformed to, or did not conform to. However, permanent paper standards also function as an aid to precise communication for both parties in a purchasing situation. If the seller can say, "My product meets Standard Such-and-Such, and I can prove it," the consumer should likewise be able to say, "I will accept this shipment as soon as I check it out to confirm what you say."

The German standard, however, is hard for the customer to use, because it relies on some expensive and time-consuming tests. Calcium carbonate and pH are not mentioned in the standard. There are three strength measures, accelerated aging (for the most permanent classes) for 24 to 30 days, and calculation of a formula to determine "lifespan classes." Purchasers who wanted to monitor compliance would have to have access to those three test machines and an aging oven, along with someone who knows how to operate them, in order to get the test figures to insert into the formula. The seller would have to wait till the aging results were in before the shipment could be accepted. This would disrupt the commercial transaction.

As an alternative, most monitoring for the consumers could be done ahead of time by some central agency, and lists of qualifying papers published at regular intervals. This is not likely to happen in the U.S., where central control is unpopular, and it would not enable the consumer to check up on individual shipments. Most purchasers would end up relying on suppliers' assurances that the shipment in question meets the standard. The purchaser would be safe some of the time, but not all the time. Institutional customers that do their own monitoring have found that a surprisingly high percentage of all shipments do not meet specs even when those specs are spelled out in a purchase order.

The Question of Journals

A couple of people mentioned the unsolved problem of journals and magazines, many of which are printed on lightweight coated (LCW) paper, which is made from mechanical pulp and thus contains lignin. Most journal publishers are not likely to switch to higher-priced freesheet. A solution to this problem was mentioned by two people: make LWC of alkaline carbonate-filled groundwood. This will probably happen anyway, because industry is going in that direction and has already had some success in Europe. Cultural institutions know that the life of journals and newspapers can be extended by deacidification. It would be cheaper for them if this process were performed during the manufacturing process, in effect.

Needed Research

An imposing list of permanence-related topics was compiled by the small discussion groups. Accelerated aging methods, and correlation of accelerated aging with natural aging, were mentioned frequently in discussionsof the larger group. In fact, two of the eight small discussion groups were on this very topic. The other groups were:

The End-user
Chemistry & Physics I & II
Optical Properties and Discoloration
Broader Issues.

The day following the workshop, four people stayed on and drafted a "Request for Research Proposals." The sponsors are now being asked for their input before it is issued.

[This report will be continued in a future issue. It will cover the papers given at the workshop and more details on research and testing.]</p>

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