The session was a series of short presentations by the panelists followed by a question and answer session that was open to the floor as well as pre-submitted questions from the AIC membership.
The panelists were: James Burd, President and CEO of Preservation Technologies, LP; Michael Ramin, Project Manager Research/Analytics, Nitrochemie; Dick Smith, owner Wei T’o Associates; Fenella France, Chief, Preservation of Research and Testing Division, Library of Congress; Nora Lockshin, Smithsonian Institution Archive on behalf of Anna Friedman, Conservator, National Archives and Records Administration.
The first presentation by James Burd “Bookkeeper Deacidification: The Chemistry Behind the Process” began with a review of Preservation Technologies’ twenty years in business, including an overview of their products and services as well as the scope of their operations. Mr. Burd spent the most time describing the Bookkeeper process, that it is a non-toxic, non-flammable, non-VOC, odorless process that does not use solvents or produce effluents. The alkaline agent is magnesium oxide (MgO) and in the mass-process it is delivered in an inert suspension liquid in which the books are immersed, relying on an electrostatic attraction to cellulose to deposit the MgO in the paper. Mr. Burd referenced recent research at the Canadian Conservation Institute and assorted technical studies at the Library of Congress in support of the effectiveness of the Bookkeeper process and reminded the audience that whatever the challenges presented by brittle collections, the greatest risk is doing nothing.
Michael Ramin followed with his talk “Durability, Quality Control, and Ink Corrosion Treatment with the Papersave Swiss Mass De-Acidification Process”. Papersave is a solvent based process using hexamethylene disiloxane (HMDO) as the solvent and magnesium as the alkaline agent. For treatment, the books are placed in metal baskets, which are then placed in a chamber for pre-drying, treatment, post drying and re-conditioning. Papers, books and drawings can be treated by this process. The items are treated in a vacuum chamber which ensures saturation by the treatment solution followed by the reconditioning process which allows moisture back into the chamber and the moisture in the air activates the deposited alkaline reserve. The company performs regular quality control in line with the German Institute for Standardization (DIN) and has retained 12 years’ worth of data including surface pH and XRF measurements to determine distribution of alkaline reserve. Papersave also has sample sets for real time ageing at five and ten year intervals. According to Mr. Ramin, the Papersave process is alos safe for paper that has iron gall ink corrosion since “through the treatment the acid is neutralized without removal or migration of the ions, on the contrary some of the iron is bound and neutralized.”
Dick Smith’s talk “Wei T’o Paperguard: Comprehensively De-acidifying, Stabilizing and Strengthening Paper” was third in the line-up although all the presenters acknowledged Mr. Smith as a foundation researcher and advocate for the mass de-acidification of paper. The original Wei T’o product was one of the first on the market for the treatment of acidic paper and Mr. Smith spent a portion of his talk describing how he became interested in the science of paper de-acidification, explaining that even though a piece of paper is thin, penetrating the surface with an even distribution of an alkaline agent is not an easy task to accomplish, especially 30-40 years ago when the technology was not very advanced. Mr. Smith then went on to profile a new Wei T’o product, still in the development phase, called Paperguard which not only de-acidifies, but also protects paper from fungal growth and pests. It is a zinc-based process that is environmentally sustainable since the by-products of the process are recoverable.
The fourth presentation was by Fenella France “Taking the Measure: Treatment and Testing in Mass Deacidification” and started with a review of the Library of Congress’ research into the mass de-acidification process which began in the 1970’s and expanded in the 1990’s. While the Library of Congress has vast historical collections, they are also still taking in acidic collections from all over the world and their current mass de-acidification treats more late 20th and early 21st century books from India, Spain, USA, etc. than 19th century material. The initial goal for the Library’s research was to establish a process that would deposit an alkaline reserve that tripled the longevity of an item, Bookkeeper was selected and a treatment facility was installed on-site at the Madison building. Testing and quality control is ongoing, but Ms. France sees a real need for the library research community to do more independent testing and not rely on vendor sources since there is too much variation in test methods to allow for meaningful comparison of data. A single measure that could be applied across the different mass de-acidification processes would enhance the assessment process and allow for agreement on the definition of progress.
The final presentation was Nora Lockshin on behalf of Anna Friedman “Evaluating De-Acidification After 20 Years of Natural Aging”. Ms. Friedman’s research focused on a treatment group from a 1989-1991 project at the Smithsonian Institution Archives where over 500 architectural drawings out of a record group of over 2,000 were sent out for de-acidification with Wei T’o Soft Spray or an aqueous bath with Magnesium Bicarbonate. Ms. Friedman used surface pH testing and colorimetric measurements at 5 points across the front of a drawing to evaluate the long term effectiveness of the de-acidification treatments. The colorimetric evaluation did not show any trends, but the surface pH showed that the application of Wei T’o was very uneven across the surface of the document. This would make sense given the application process of Soft Spray. However, comparison with a control group showed that documents that had been treated for mass de-acidification did have a higher pH after 20 years of natural aging.
The open discussion that followed began with a submitted question
SubQ: Is spraying of individual items as effective?
A: Papersave and Paperguard cannot be applied singly- mass only
Q: (Emily Rainwater) As a user of post-Bookkeeper treated items, she finds a lot of residue from handling the books, e.g. turning pages.
A: (Burd)- The particulates should go away as the treated book ages. (France)- Early in the development of the Bookkeeper process the particles were fairly large; they’re smaller now, so the white powder problem should go away.
Q: (Eric Hansen)- Italian conservators and others have complained that Bookkeeper changes the feel of the paper. Will Bookkeper address this question in a direct way so that this issue can be settled?
A: (Burd)- People really shouldn’t be able to tell, he has spray with him and offered to let people spray samples of paper and feel for themselves. The particle size is small and the quality control protocol of mass de-acidification is rigorous. (Smith)- Is particle size really the issue? Are we measuring what we think we’re measuring in terms of quality control? The TAPPI tests that we generally use are a standard, but are not precise to our need.
Q: (John Batty)- What does Mr. Burd mean by “pure” alkaline reserve?
A: (Burd)The magnesium that Bookkeeper uses is of high purity, but also there is no residue of other treatment fluids after the process is completed since the Bookkeeper process is full recovery.
Q: (John Batty)- To Mr. Smith: are you planning to treat artist’s materials to a specific pH?
A:(Smith) Not just to a specific pH, but also using zinc to ensure fungal and pest prevention.
Q: (Johanna P) To M. Burd, how is the benefit to ink measured, given that iron gal ink is supposed to stay acidic? Also, what about the color change or yellowing of treated items?
A: (Burd) If you have an ink you want to stay acidic, don’t treat it with a de-acidification process. If you want to stabilize iron gall ink and protect the substrate as well, then the Bookkeper process can be directed toward strengthening of paper.
A: (Ramin)- Non aqueous is better treatment since the paper is not as stressed.
A: (Smith): Commenting on paper yellowing after treatment by Wei T’o; he took yellowing as a sign of effectiveness since it demonstrated penetration of spray (this was in the early days) but don’t give up on de-acidification, work on delivery of the alkaline reserve.
A: (Burd)- Commenting on yellowing- Since the Bookkeeper process doesn’t use a solvent, there shouldn’t be any yellowing. Some researchers have spotted yellowing due to aging of magnesium, but Burd thinks the books would probably have yellowed anyway, so the magnesium application just changes the characteristics of the yellowing. Burd went on to comment that yellowing is only present in artificially aged paper samples, and that 20 years is not long enough for real time aging to be conclusive.
A: (Ramin) Papersave tests show some yellowing in ground wood and to comment on mold remediation, the Papersave drying process kills mold, which is a side benefit. Once treated, collections tend to have better storage conditions, so mold is less likely to grow again
A: (Smith)- Zinc has potential for mold and pest prevention in addition to mass de-acidification.
A: (Burd)- Alkalization does help with mold prevention
Q: (Ursula ?): Could there be more natural aging studies? To Ms. France, given ten years of using Bookkeeper, are you doing any studies? To Ms. Lockshin: were the treated papers stored differently?
A: (France)- Yes, the Library of Congress is initiating a long term study.
A: (Lockshin) all treated drawings were encapsulated and then opened for analysis but were otherwise stored together.
Q: (Cathleen Baker): the audience knows a lot about the complexity of paper, but the ads and trade lit is a little unsophisticated and implies that mass treatment should be readily applied, whereas selection is a more complex process. What about the effect of mass de-acidification on lignin?
A: (Burd)- This has been reported in literature, but if you attack lignin you will make paper weaker, to prevent this effect, don’t select items that are brittle where the lignin or cellulose is already weak, they can’t be rebuilt by mass de-acidification.
A: (Lockshin) Commented that the Smithsonian receives many reference calls, people have seen an ad for a product and want information on its effectiveness.
Q: (Renate Mesmer) The Folger Library has just started a Bookkeeper project and wanted to comment that handling of books for the Bookkeeper process is extreme, given the fanning out and agitation. They have also found very high amounts of white deposits, and given these high amounts of surface deposits, is anything going to the core of the paper?
A: (Burd)- Since we don’t use solvents we have to fan the books so that the alkaline particles can make their way into the paper. If a book is too delicate for the mass process, then use the single item process. Distressed to hear that there are a lot of white deposits. Porosity of the paper is the dependent factor on penetration, but acids migrate toward the alkaline particles so this shouldn’t ultimately be a problem.