Unbuffered vs. Buffered Paper, Plus a Rant on the Need for Chemical Understanding by Archival Professionals

Question

Under what conditions should either buffered paper or unbuffered paper materials be utilized by archives in the storage of archival materials?

Answer

Both types of paper will become acidic over time; it is merely a matter of how soon this acquired acidity develops. Unbuffered paper does not contain any alkaline buffer and has a pH at the time of the paper’s creation of 7 to 7.5. Buffered paper (paper containing an alkaline buffering agent to protect against the spread of acidic compounds) was developed to prolong the chemical stability of paper materials used in the storing of archival materials, by causing any migrating acids to become inert. The alkaline substances most often contained within buffered paper are calcium carbonate and magnesium carbonate, maintaining an approximate pH of 8.5. In order for buffered paper to stay “. . . acid-free for long periods of time (e.g., 500 years) should have approximately 3 percent precipitated carbonate by weight of paper.”

For many years, it was recommended for an archives to use unbuffered paper when there was uncertainty as to if buffered paper would have a damaging effect on archival materials. In recent years, this issue has come to be less as important as is the quality of the paper: if the paper becomes acidic quickly, it does not matter whether it is buffered or not. Buffered paper products are acceptable for use with most books, paper documents, cellulose nitrate and acetate negatives, artistic prints and drawings (except those with pastel and charcoal, or that have been tinted), black-and-white motion picture film, and plant-derived materials.

Personally, I rather the unbuffered, simply because it is better to have as few chemical additives as possible in contact with archival materials. Plus, we do not know yet if down the road buffering elements will be found to have an unaccounted-for effect on archival materials. Granted, the buffering agents are carbonates, but still, a number of archival preservation materials once believed safe have turned out over time to have actually caused damage to historic records. It is also important to note that as far as research into the chemical effects of materials on historic materials within an archival setting, little sustained scholarship or research has been conducted. Archivists need to build strong relationships with chemists in university settings, because there is more to archival preservation than Mylar sheets, Filmoplast mending tape, and book-spine repair.

I once-upon-a-time asked in college for a course on Chemical Interactions of Historical Materials for Archivists, but was thought this was too broad and unnecessary. One of an archivist's most basic responsibilities is to understand how a large variety of materials upon which historical information and records are recorded breaks down with time, in different storage conditions, and with contact to common household chemicals. I was fortunate to have had a total of two years between high school and college in chemistry, and had a major interest in minerals and magnetism growing up (all good things for understanding film and photo preservation). Yet, many of the average library science, public history, and archival studies programs fall short of offering this very important training. If you talk with many students about the differences between buffered and unbuffered papers, or the difference between silver halide cellulose nitrate film, few will be able to offer a coherent explanation of the differences. Even so, a number of fellow young archivists I've spoken with over the past three years have expressed enormous interest in taking a class as I suggested, or even taking conservation courses (though these are often emphasized for museum studies students and professionals). I find it ironic that as more records are being born digitially, archival educators advise students to take technology and computer courses.

Yet, when a 1785 map is disintegrating because of moisture damage, archivists pick up the phone most often to call first for finances to get the item "preserved and stabilized," then to have a conservator come in and charge a large fee to advise you on the best steps for the maps stabilization. After consulting with several conservators over the past few years, I've learned that many of the tasks conducted within archives by conservators could indeed be done by archivists (as I did with a set of historic railroad blueprints that I was told were "impossible to flatten and scan"), if a little effort, creativity, and research were conducted. Yes, archivists need to be tech smart, but science smart is equally--if not more so--a vital element of archival preservation. There's more to historic records than information: there's science.

If any of you have been following the news, you may have heard of the final rediscovery/acquisition of a famous, mostly unheard for decades collection of homemade jazz recordings by the pioneer of the 33 1/3 rpm record, William Savory (http://www.abajournal.com/magazine/article/a_trove_of_historic_jazz_recordings_has_found_a_home_in_harlem_but_you_cant/). The enormity of the records collection that has been stored for years is truly astounding. However, the records--some of which are recorded on various types of metal disks--are becoming unplayable. Obviously, the answer is digitization before the music is lost, but first of all, the records have to be cleaned and repaired where possible. In order to do this, the National Jazz Museum in Harlem has hired an old record industry pro who has extensive knowledge about the various materials used in the creation of various types of record discs/platters. He is slowly cleaning with specific materials each record, then seeing if it can be heard still or the music saved at all, and then it is digitized. I wonder how many young archivists today would have the chemical understanding to know the differences between all the different materials used in the creation of records. My grandfather records his own bluegrass albums in his basement, and I own some of them--I still can't tell you many of the chemical processes used in or the chemical deterioration of various types of records over time. Archivists, let us take steps to gain a base of knowledge on which to build, rather than trying to build the tower with plastic foundation bricks.

Resource for Further Study

“Storage Enclosures for Books and Artifacts on Paper.” Storage and Handling 4.4 leaflet. Northeast Document Conservation Center Preservation Leaflet series. Viewed on February 11, 2009, at http://www.nedcc.org/resources/leaflets/4Storage_and_Handling/
04StorageEnclosures.php.

The Northeast Document Conservation Center’s Preservation Leaflet series provides practical, professional information for the preservation of historic paper and photograph materials. Leaflet 4.4 deals with the chemical stability of and durability of paper and plastic storage materials used for preservation storage of historic materials. It is a very good, brief resource to explain the complicated issue of the acidity of paper materials.

Albright, Gary, and Monique Fischer. “Care of Photographs.” Photographs 5.3 leaflet. Northeast Document Conservation Center Preservation Leaflet series. Viewed on February 11, 2009, at http://www.nedcc.org/resources/leaflets/5Photographs/03CareOfPhotos.php.

The Northeast Document Conservation Center’s Preservation Leaflet series provides practical, professional information for the preservation of historic paper and photograph materials. Leaflet 5.3 addresses controlling of the storage conditions for historic photographs, which also includes the enclosures (either paper or plastic) used for their storage. The portion of this leaflet relevant to unbuffered and buffered paper materials comes in the description of the types of paper enclosures available for photographs.

“Buffered And Unbuffered Storage Materials.” Conserve O Gram (National Park Service) 4.9(July 1995). Viewed on February 11, 2009, at http://www.nps.gov/history/museum/publications/conserveogram/04-09.pdf.

This NPS newsletter article provides a brief but detailed summation of the unbuffered and buffered paper situation. The best part of this article is that it comes with a chart of archival materials (and columns for both unbuffered and buffered paper materials) for which of the two paper materials is best for storing archival items. However, this article is from 1995 and not as up-to-date as the information provided by Northeast Document Conservation Center.

Is Digitization the Answer for Preserving Paper-Based Library Materials?

The digital age has wrought a reliance on electronically-transmitted and formatted materials for use by the public. Digitization of records has come over the past twenty or so years to offer a means of reformatting deteriorating paper-based library materials, ensuring the information contained in the ink and paper is available for long-term access. Digitization offers several advantages for libraries in terms of preservation, providing access, and removing severely-deteriorated materials from library shelves in order to protect the library’s other materials. Since around the 1920s, microfilm offered such a solution for libraries, archives, and other cultural institution fighting the battle of the rot and ware of paper-based materials. However, microfilming requires a great deal of time, a lot of oversight during the whole process, can be costly, requires elaborate equipment, and often has to be outsourced to microfilming vendors. Most patrons of library do not enjoy the experience of utilizing microfilm, as eye fatigue and continually having to reload rolls of film on a viewer wear on a user’s patience.

Over the past twenty years especially, digitization has become one of the main answers for libraries and archives in creating use surrogates of original materials for public handling, in order to protect the original items and sustain the availability of the items in their original format for as long as possible. However, digitization carries many of its own problems, among which are long-term storage and maintenance of digital materials, complete substitution of the original materials for electronic copies, and the loss of information only available from the original format of the paper-based materials. The most important questions concerning digitization for libraries still have yet to find concrete solutions, while in the meantime libraries continue to digitize for short-term benefits initially. Is digitization the solution for the preservation of paper-based library materials? Is there a difference between “digitization for preservation” and “digital preservation”?

Books and other paper-based records carry with them uniqueness, as well as the record of the physical impact they have received from people and time. Library collections are increasingly focusing on digital collections and digital curation—with digitized paper-based records such as archival material fitting within this movement. However, the concept of “physical artifact” that is embodied within old books and manuscript collections imbues library preservation with the need to take steps to ensure the longevity of the original materials, through providing both a use copy of the fragile originals and sustaining the integrity of the original materials. In a January 2010 issue of The Library Quarterly, Paul Conway echoes this view in his study of the conversion to digitization within libraries and archives, recommending that libraries:

"Continue to give pride of place to preservation quality environments and the buildings required to sustain them. Perhaps for decades to come, material culture artifacts will serve as the ultimate backups for their digital surrogates. Preservation environments buy time for careful decision making and represent highly tangible commitments to long-term preservation" (“Preservation in the Age of Google,” 75).

Even so, the Association for Research Libraries Preservation of Research Library Materials Committee notes that, with all preservation and reformatting options for paper-based library materials, there are benefits and shortcomings. The Committee stated in a June 2004 report that

"Digitization increases the capture capability for many types of paper-based material, such as oversize and color items, for which there has been no effective reformatting strategy to date. Functionality, such as zooming capabilities, allows users to examine more closely fine details and produce a variety of outputs to suit different needs. Digital facsimiles better reproduce the navigational experience of a book than does the linear format of microfilm" (“Recognizing Digitization As A Preservation Reformatting Method,” 2, http://www.arl.org/bm~doc/digi_preserv.pdf).

Even with these reasons to utilize digitization, it is important to note that the ARL recognizes, as the title of the report suggests, that digitization of paper-based materials for preservation is an issue of “reformatting,” not necessarily substitution of the digital surrogate for the original item. This goes counter to a popular attitude amongst library professionals, which is promoted, as Robert Bee discusses in an April 2008 Library Quarterly issue, by “The idea that texts are information that can be reformatted without loss permeates the professional library literature, a view that tends to ignore the importance of a text’s medium and physical format” (“The Importance of Preserving Paper-Based Artifacts in a Digital Age," 180).

Original formats of paper-based library materials carry with them unique “historical dents” created through the agency of various people and the impact of time’s wear. Reproducing these alterations and “dents” are difficult because of their variety on paper-based materials: “Faithful digital representation is even more difficult with manuscripts. Take a look at the Library of Congress’s online versions of the Works Progress Administration (WPA) Life Histories, which requires some complex notation just to represent a small handwritten correction” (Daniel J. Cohen and Roy Rosenzweig, “Digital History,” http://chnm.gmu.edu/ digitalhistory/digitizing/1.php). Digitization for preservation, despite its benefits for “reduce[ing] wear and tear on fragile items,” remains a tool that is to be fit within a library or archives overall preservation program, for “Preservation remains a secondary benefit of digital projects” (Trevor Jones, “An Introduction to Digital Projects for Libraries, Museums and Archives; http://images. library.uiuc.edu/resources/introduction.htm). There is no substitute of the original paper-based record. Searchability, unlimited access, and ready availability will continue to push digitization of library materials for preservation and research needs, and the public will understand only that they want the materials available digitally—not necessarily caring about the preservation issues involved. Public pressure and funding objectives will push libraries to use digitization as a primary means of preservation in the future.

Yet, as pointed out briefly already, Richard Rubin succinctly identifies the most pressing issue regarding digitization for preservation: “The problem is fixity. That is, print materials have some permanence, but electronic text is impermanent. Ironically, the ease with which digital material can be altered raises serious questions about its capacity to serve as a preservation technique” (Foundations of Library and Information Science, 3rd ed., 2010, 259). Long-term preservation of the digital formats most often used to capture digitized records (such as PDF and TIFF) are only reliable as a preservation medium if they can be migrated to newer formats, be able to have guaranteed continual access on technological devices, and have no or little loss of data representing the originally-scanned record. This is where digital preservation—or the long-term curation of digital materials—comes into play, and where the difficulties embodied within both digital preservation and digitization for preservation become joined together. There are no agreed upon long-term digital preservation formats. Rather, there are digital formats that limit or have no loss of digitized material within a certain amount of stored time or certain number of repeated uses of the original digital records. Bee points out that “Digitization offers the potential of much better surrogates for documents, but it also is fraught with danger. Digitized information erodes more quickly than print does, contains errors, must be continually “refreshed,” and is encoded on constantly changing software and hardware” (“The Importance of Preserving,”191).

The costs involved with creating, maintaining, and promoting digitized paper-based library materials can be just as expensive as microfilming, with the major distinction being the great disparity in length of longevity of the storage medium. Digitization relies on magnetic and optical media that require electricity for the basis of access. As more and more digitized library materials are places on the Web, access of these materials also becomes dependent on the type of web browsers used, computers and other digital devices utilized by users and patrons, and the ability of different people from different socio-economic backgrounds to be able to obtain access to those materials.

Digitized library materials give more opportunity for the public and researchers to discover the records without having to be physically present in the records’ repository. Even so, this wider access and discovery opportunity also brings up the “Google question” of copyright issues regarding digitized materials. Libraries do not have the luxury of time to check on the copyrighted nature of all the materials they digitize, though they must according to professional practice and legal restrictions. Thus, digitization offers great flexibility as a preservation tool, but not as the substitute for what others have produced or contributed to a particular produced record within a library’s collection: “Even after digitization, original documents and artifacts must still be cared for” (Jones, “An Introduction,” http://images.library.uiuc.edu/resources/introduction. htm).

In the end, digitization for preservation will continue to operate for the immediate future as a tool only for preservation for most materials, with some materials demanding digitization as the only way to save the information contained in the materials. Long-term, advances may be made to give digital records a storage and use stability of 25-50 years, yet a step below microfilm but a great improvement over current digital storage abilities. Rubin sees that “as new digital storage techniques are developed, digital preservation will become increasingly common” (Foundations of Library 2010, 260). Still, there will be no substitute for the preservation of original paper-based library materials in their original, non-digital format—-at least until digital-born publications and records begin to outnumber and to outperform the amount produced of and opportunities offered by hard copy paper-based materials. Digitization for preservation is a good weapon in the fight to preserve, but just like microfilm has not completely negated preserving the original paper-based materials, so too will digitization not—nor should it—replace the hard copies of the printed word.