Volume 18, Number 7
Nov 1994

ARSAG Conference Papers, Pt. 2

Marc Walckiers (European Foundation for Library Cooperation, Brussels) reported the results of EFLC's questionnaire survey of papermakers and publishers for the second edition of the European Directory of Acid-Free and Permanent Book Paper. (The first edition is described on p. 46 of the August 1993 issue of the Abbey Newsletter.) They identified 120 permanent book papers (320,000 tons), which he says largely satisfies the demand. Costs of alkaline and acid papers are equivalent. The papermakers are gradually converting, and libraries and archives are demanding permanent paper, but 70% of the publishers are not aware of permanent paper, or of the EFLC resolution urging them to use it.

The future looks good, because the ISO standard for paper permanence has been published, and the European Union has published a directory of permanent paper. But coordinated action by libraries and archives is essential, and universities must publish on permanent paper.

Bertrand de Montgolfier (Papeteries Canson et Montgolfier, Annonay) gave a paper called "Quel coût de papier pour quelle permanence?" or "What Price Permanence?" He described the ISO standard and the use of the infinity sign, but said "permanence" sounded like an absolute concept; he preferred "long life." The standard does not mention optical brighteners in connection with permanence, and yellowing does not seem to be perceived as an obstacle to reading of documents. But the low kappa number requirement (5 or lower) may make it impossible to include a high percentage of recycled fiber in permanent papers. [In fact, the EFLC survey did not turn up a single permanent paper that contained recycled fiber.] TCF and ECF (totally chlorine free and elemental chlorine free) bleaching methods, he said, have absolutely no impact on the permanence of paper.

Mr. Montgolfier said he had surveyed his company's merchants and finds that specific demand for permanence is very low. Customers demand brightness, thickness, opacity, and price; and price depends on thickness, reel vs. sheetfed, size of order, whether order is placed through a mill or a merchant, and the volume of the year's business from the customer.

John Havermans gave a preliminary report of results from the massive STEP Project, "The Effects of Air Pollutants on Accelerated Ageing of Cellulose Containing Materials." Although a more recent summary of the results was published in the October issue of this Newsletter after the study was finished, Havermans' nine-page paper presents much of the substance in clear form, with graphs, tables, and diagrams. (Directions for ordering the 500-page report are given in the October issue.)

Certain things from Havermans' paper stick in one's mind: They used 35 aging conditions and had 9000 data points; papers containing calcium carbonate absorbed the most pollutants, and groundwood papers absorbed next most; and nitrogen dioxide and water both increased the uptake of sulphur dioxide, i.e., had a synergistic effect.

Edward Zinn (Image Permanence Institute, Rochester) spoke on the effect of oxidizing gases (ozone and nitrogen dioxide) on color photographs. (His paper was coauthored by James M. Reilly, Peter Z. Adelstein, and Douglas W. Nishimura.) He said that IPI had embarked on the study reported here in order to identify the pollutants most harmful to color images in film and on paper, in preparation for a long-term study using ambient or near-ambient conditions. They paid particular attention to synergistic effects, which turned out to be complex. Hydrogen sulphide and sulphur dioxide had little effect without oxygen. Ozone and nitrogen dioxide both faded thermal (computer-output) prints and color positive film. Nitrogen dioxide affected them less, but unlike ozone, it does not decompose on indoor surfaces, and is hard to control with air purification systems.

Xuejun Zou of Paprican (Pulp and Paper Research Institute of Canada) gave a paper coauthored by Norayr Gurnagul, "The Role of Lignin in the Mechanical Permanence of Paper: Part II. Effect of Acid Groups." He did not believe that the impermanence of mechanical pulps had been demonstrated yet; they deteriorated, he said, only when they had not been manufactured under neutral or alkaline conditions. (In his introduction he does not mention presence of calcium carbonate or other alkaline buffer as a way of keeping the paper alkaline after it was made.) The work he reports in his paper was done to check out the possibility that acid groups, mainly carboxylic acid groups formed in the cell wall through oxidation of lignin and other fiber chemical components, might be responsible for lowered pH and consequent deterioration of the fiber. Sulphonic acid groups may also be introduced into the hemicellulose and lignin during CTMP, CMP or sulphite pulping and bleaching.

They made handsheets with mechanical pulp containing each sort of acid group, neutralized the acid several ways, aged the handsheets, and noted that a higher pH improved permanence--in effect, demonstrating that both deacidification and washing with tap water makes paper last longer.

Christopher Calnan reviewed the processes recommended in the last 90 years to make longer-lasting leather and to stabilize the condition of deteriorating leather. Retannage with aluminum triformate in aqueous methanol was recommended in the mid-1980s, and it did improve leather's resistance to acidic deterioration in the aging oven, but it tended to stiffen and darken the leather. Research continued, and a better retanning agent was found, aluminum alkoxide.

There are actually a number of aluminum alkoxides on the market; you have to specify which one you are using. Data from trials using 2% aluminum alkoxide (AOC 1010X) is presented. All the alkoxides are soluble in organic solvent; they increase shrinkage temperatures (Ts) 20°-30°C; they keep the pH of treated leathers about one point higher than that of untreated leathers after aging; and they keep the leather from weakening as fast during aging. The Ts of treated leather falls just as fast during aging, but because it started out higher, the life of the leather has been extended nevertheless. And, just as newer papers benefit more from deacidification, newer leathers profited more than old leathers from retannage with aluminum alkoxide.

The leather hardens somewhat from the retannage, but flexibility can be restored by dressing with a 10% solution of cold tested neatsfoot oil in white spirit.

During the question period, Rene Larsen said he didn't think this treatment made a big enough difference. Calnan said the STEP Project had shown that Ts was very important; to make a significant change in leathers with low Ts, maybe you have to use more aluminum alkoxide.

Peter Z. Adelstein (Image Permanence Institute) gave a paper coauthored by James M. Reilly and Douglas W. Nishimura on "Recent Changes in Recommended Storage of Photographic Film." He started out by stating four Great Truths about storing film, which he called "philosophy of storage":

1. The usually recommended conditions, of 20°C and 50% RH, are not good enough. In the last 15 years, there have been a lot of complaints of deterioration in collections that maintain those conditions. Research has increased at several centers, including IPI.
2. There is a potential tidal wave of deteriorated cellulose triacetate coming. The first reports of unstable cellulose triacetate came from Calcutta in 1955, but it was still regarded as stable.
3. Copying programs will not be able to keep up. Copying is not the answer.
4. The only practical approach is proper storage.

The essential elements of proper storage, he said, are:

• Colder is better.
• Low relative humidity retards degradation.
• Atmospheric pollutants should be avoided.

He summarized the findings of the three-year cellulose acetate study that IPI finished in 1990. One of the points that bears repeating is that relative humidities as high as 50% can be tolerated for long-term film storage as long as the temperature is lowered to about 0°C in compensation.

Jim Wheeler (Tape Archival and Restoration Services, Belmont, Calif.) was one of three speakers on videotape preservation, who did not always agree with each other on certain points, such as whether or not the sticky shed syndrome can be cured by baking the tape in the oven (the other speakers did agree, however, that the temperature should not exceed 60°C). The primary enemy of tape life is high humidity; he recommends an RH of around 25% and a temperature of less than 22°C (70°F). Temperature is a big factor in deciding how often to rewind. If the tape is stored at 80°F, it should be rewound every four months or so, but if it is stored at 50°F, it will only have to be rewound every 25 years. [Of course, by that time, the player would be obsolete and it would be time to transfer the tape to a new format anyhow. The format recommended for archival purposes is the Betacam-SP.]

It is also important to control fluctuations in temperature and humidity in the storage area. An economical way to provide the best conditions for masters and critical tapes, he said, is to set up a special well-insulated room within the archives.

To prevent accidental erasure, disable the record/erase function on the tape cassette and in the player, and never check a tape with your luggage at the airport, because the conveyor belt motor may erase it. (It will also erase the hard disk if you check your laptop.) The X-rays at the security checkpoint are OK. When shipping a tape, use 2-3 cm of packing on all sides to provide distance between it and any magnet it may come near.

He also reminded the audience of the basics of tape storage: store tails out, vertically; don't store in acid cardboard containers or vinyl boxes, and so on.

John Mallinson, who spoke on the same topic, made a startling recommendation: Shortly after a format becomes obsolescent, the tapes are useless and should be thrown out. As part of a long-term strategy, he recommended transferring any tapes that need to be kept for more than 20 years to movie film (a very expensive procedure) or continuously transferring images to a more recent video recorder format, preferably digital, on a professional recorder.

At the end of the session on videotapes, the session chairwoman summarized the talks and asked the speakers to please give those present a little hope; wouldn't optical disks help? And Mallinson's reply was, "I would say there is very little hope." Edward Cuddihy, of the Jet Propulsion Laboratory, said that the newest space mission would use solid state memories, but of course no one suggested this as a solution for archives.

For a copy of the preprints (title: Environnement et conservation de l'Žcrit, de l'image et du son), write or fax ARSAG, 36, rue Geoffroy St Hilaire, 75005 Paris (fax 33-1- 47 07 62 95). The price is 350 FF.