Mass deacidification is a term used in library and information science as one possible measure against the degradation of paper in old books, the so-called "slow fires". The goal of the process is to increase the pH of acidic paper. Although acid-free paper has become more common, a large body of acidic paper still exists in books made after the 1850s; this is because of its cheaper and simpler production methods. Acidic paper, especially when exposed to light, air pollution, or high relative humidity, yellows and becomes brittle over time. [1] During mass deacidification an alkaline agent is deposited in the paper to neutralize existing acid and prevent further decay. [2] Mass deacidification is intended for objects on acidic paper that will be lost if no action is performed.
Mass deacidification—along with microfilm and lamination—was developed during the early and mid-20th century as a response to the chemical process of hydrolysis by which the fibers that constitute paper, providing its structure and strength, have their bonds broken, resulting in paper that becomes increasingly brittle over time. Environmental pollutants can react with paper to form acids that promote oxidation, creating more acid as a by-product, which results in a positive feedback loop of autocatalytic destruction. [3] Supported in part by grants from the Council on Library Resources, William J. Barrow conducted research into paper decay and found that no more than three percent of books published between 1900 and 1949 would survive more than fifty years. In response to this, a Standing Committee on the Preservation of Research Library Materials was formed by the Association of Research Libraries (ARL) in 1960. [4]
Barrow also invented an aqueous process to neutralize acid in paper while depositing an alkaline buffer that would slow the rate of decay. [5] In addition to Barrow's original method, both non-aqueous—employing organic solvents—and vaporous—the Library of Congress' DEZ (diethyl zinc) treatment—methods of achieving the same results have been researched in an attempt to reduce time, labor, and cost requirements. [6]
One technique proposed is to place books in an evacuated chamber, then introduce diethylzinc (DEZ). In theory, the diethylzinc would react with acidic residues in the paper, leaving an alkaline residue that would protect the paper against further degradation. [7] In practice, the heating required to remove trace water from the books before reaction (DEZ reacts violently with water) caused an accelerated degradation of the paper, a series of chemical reactions between DEZ and other components of the book (glues, bindings), caused further damage, and produced unpleasant aromas. In the 1980s, a pilot plant for mass deacidification, using this process, was constructed by NASA and was tested on books provided by the Library of Congress. [8] In 1986 it was discovered that the DEZ had not been removed in one of the deacidification runs and pooled in the bottom of the chamber, possibly remaining within the plumbing. DEZ is violently flammable when it comes in contact with either oxygen or water vapor, so the vacuum chamber could not be opened to remove the books within. Eventually, explosives were used to rupture the suspect plumbing; suspicions of the presence of residual DEZ were confirmed by the subsequent fire that destroyed the plant. In his book Double Fold , Nicholson Baker discusses the failure of the NASA program at great length.
The chemical company AkzoNobel made later attempts at refining the process. The risks of fire and explosions were reduced by a better process design, however, damage and odors remained a problem. In the end, AkzoNobel determined the process was not a viable commercial proposition and shut down their research at the end of 1994.
These are the results that the Library of Congress expected of an ideal mass deacidification treatment in 1994:
Faculty members of the Slovak University of Technology added these further requirements:
All of the processes imparted an adequately high pH in studies conducted by the European Commission on Preservation and Access, the Library of Congress, and a team of scientists from the Centre de Recherches sur la Conservation des Documents Graphiques in the early and mid-nineties. BookKeeper produced a pH of 9–10. [9] CSC Book Saver yielded a pH of 8.78–10.5. [11] Wei T'o gives 7.5 to 10.4, [12] and Papersave gives a pH of 7.5–9. [13]
The same studies also found that the processes had adverse cosmetic side effects. BookKeeper left "a palpable residue", clamp marks on the covers, and caused some of the colored inks to rub off. [9] CSC Book Saver left a "white powdery deposit" on books. [14] Papersave caused "discoloration, white deposit, Newton's rings, bleeding of inks and dyes, odor and different 'feel' of the paper." [15] Wei T'o caused "odor, white residues, rings, cockling, (yellow) discolorations and adhesive bleeding." [16]
Conservators from the British Library acknowledge that the existing mass deacidification processes are still being developed and further research needs to be conducted on their chemical and mechanical effects. [17]
Several commercial deacidification techniques are on the market as of 2008 [update] :
BookKeeper, CSC Booksaver, Papersave, and Wei T'o are also available as hand-held sprays.
While deacidification has been adopted by major research libraries such as the Library of Congress and the New York Public Library, it is not clear whether many archives, particularly those in the United States, have followed suit. Some European national archives have tested deacidification techniques. The United States' National Archives and Records Administration (NARA), which pioneered an aqueous technique that improved upon Barrow's, chose to invest its preservation dollars elsewhere. [5] In 2000, the Chief of the NARA Document Conservation Laboratory defended the lack of a mass deacidification program by pointing to differences between library and archival collections. For example, noting that many of the papers coming to NARA were of a higher quality than those in library collections; that the Archives does not receive records from federal government agencies until they are at least 30 years old, by which time acidic paper will have already been irrevocably weakened, and that limited resources might best be applied elsewhere, such as climate control. Under the Archives' Twenty-Year Preservation Plan, emphasis was placed on achieving the "maximum benefit for the greatest number of records." [25]
Though now dated, several sources estimate the costs and suitability of deacidification treatment. Studies conducted by the Harry Ransom Humanities Research Center and the General State Archive of the Netherlands found the DEZ method might be particularly applicable to archival materials. [26] It was estimated that deacidification costs, excluding transportation and handling, during the early 1990s was $5–10 per volume. [27] During 1995–1997, the Library of Congress received $2 million in appropriations to deacidify 72,000 books using the Bookkeeper commercial method and evaluate alternative methods. The actual cost per book was $11.70. [28] Finally, a 2003 cost comparison with reformatting options per volume yielded $125 for microfilming, $50 for scanning and minimal indexing and, based on a New York Public Library project, $16.20 for deacidification. [6] However, already in 2004 Google Books was able to scan for only $10-$20 per book. [29]
As of 2022, there were five mass deacidification plants in the world. [30]
A slow fire is a term used in library and information science to describe paper embrittlement resulting from acid decay. The term is taken from the title of Terry Sanders's 1987 film Slow Fires: On the preservation of the human record.
Digitization is the process of converting information into a digital format. The result is the representation of an object, image, sound, document, or signal obtained by generating a series of numbers that describe a discrete set of points or samples. The result is called digital representation or, more specifically, a digital image, for the object, and digital form, for the signal. In modern practice, the digitized data is in the form of binary numbers, which facilitates processing by digital computers and other operations, but digitizing simply means "the conversion of analog source material into a numerical format"; the decimal or any other number system can be used instead.
Sizing or size is a substance that is applied to, or incorporated into, other materials—especially papers and textiles—to act as a protective filler or glaze. Sizing is used in papermaking and textile manufacturing to change the absorption and wear characteristics of those materials.
Acid-free paper is paper that, if infused in water, yields a neutral or basic pH. It can be made from any cellulose fiber as long as the active acid pulp is eliminated during processing. It is also lignin- and sulfur-free. Acid-free paper addresses the problem of preserving documents and preserving artwork for long periods.
In library and archival science, digital preservation is a formal process to ensure that digital information of continuing value remains accessible and usable in the long term. It involves planning, resource allocation, and application of preservation methods and technologies, and combines policies, strategies and actions to ensure access to reformatted and "born-digital" content, regardless of the challenges of media failure and technological change. The goal of digital preservation is the accurate rendering of authenticated content over time.
Preservation of documents, pictures, recordings, digital content, etc., is a major aspect of archival science. It is also an important consideration for people who are creating time capsules, family history, historical documents, scrapbooks and family trees. Common storage media are not permanent, and there are few reliable methods of preserving documents and pictures for the future.
Accelerated aging is testing that uses aggravated conditions of heat, humidity, oxygen, sunlight, vibration, etc. to speed up the normal aging processes of items. It is used to help determine the long-term effects of expected levels of stress within a shorter time, usually in a laboratory by controlled standard test methods. It is used to estimate the useful lifespan of a product or its shelf life when actual lifespan data is unavailable. This occurs with products that have not existed long enough to have gone through their useful lifespan: for example, a new type of car engine or a new polymer for replacement joints.
Diethylzinc (C2H5)2Zn, or DEZ, is a highly pyrophoric and reactive organozinc compound consisting of a zinc center bound to two ethyl groups. This colourless liquid is an important reagent in organic chemistry. It is available commercially as a solution in hexanes, heptane, or toluene, or as a pure liquid.
In conservation, library and archival science, preservation is a set of preventive conservation activities aimed at prolonging the life of a record, book, or object while making as few changes as possible. Preservation activities vary widely and may include monitoring the condition of items, maintaining the temperature and humidity in collection storage areas, writing a plan in case of emergencies, digitizing items, writing relevant metadata, and increasing accessibility. Preservation, in this definition, is practiced in a library or an archive by a conservator, librarian, archivist, or other professional when they perceive a collection or record is in need of maintenance.
The Brittle Books Program is an initiative carried out by the National Endowment for the Humanities at the request of the United States Congress. The initiative began officially between 1988 and 1989 with the intention to involve the eventual microfilming of over 3 million endangered volumes.
Double Fold: Libraries and the Assault on Paper is a non-fiction book by Nicholson Baker that was published in April 2001. An excerpt appeared in the July 24, 2000 issue of The New Yorker, under the title "Deadline: The Author's Desperate Bid to Save America's Past". The work details Baker's project to uncover what happened to the thousands of books and newspapers that were replaced during the microfilming boom of the 1980s and 1990s. Double Fold has been a controversial work and Baker states in the preface that it is not meant to be objective: "This isn't an impartial piece of reporting". The New York Times characterized the book as a "blistering, and thoroughly idiosyncratic, exposé."
William James Barrow was an American chemist and paper conservator, and a pioneer of library and archives conservation. He introduced the field of conservation to paper deacidification through alkalization.
Preservation of meaning in library, archival or museum collections involves understanding spiritual, ritual, or cultural perceptions of value for specific objects, and ensuring these values are maintained and respected. Meaning is something assigned to objects of cultural or spiritual significance based on interpretations and perceived values by user populations, a process known as social construction of an object. When moved to memory institutions such as libraries or museums, these objects of social construction require unique approaches to preservation and maintenance in order to remain relevant as representations of cultural or spiritual societies.
The term born-digital refers to materials that originate in a digital form. This is in contrast to digital reformatting, through which analog materials become digital, as in the case of files created by scanning physical paper records. It is most often used in relation to digital libraries and the issues that go along with said organizations, such as digital preservation and intellectual property. However, as technologies have advanced and spread, the concept of being born-digital has also been discussed in relation to personal consumer-based sectors, with the rise of e-books and evolving digital music. Other terms that might be encountered as synonymous include "natively digital", "digital-first", and "digital-exclusive".
Paper is a thin sheet material produced by mechanically or chemically processing cellulose fibres derived from wood, rags, grasses, herbivore dung, or other vegetable sources in water. Once the water is drained through a fine mesh leaving the fibre evenly distributed on the surface, it can be pressed and dried.
A digital library is an online database of digital objects that can include text, still images, audio, video, digital documents, or other digital media formats or a library accessible through the internet. Objects can consist of digitized content like print or photographs, as well as originally produced digital content like word processor files or social media posts. In addition to storing content, digital libraries provide means for organizing, searching, and retrieving the content contained in the collection. Digital libraries can vary immensely in size and scope, and can be maintained by individuals or organizations. The digital content may be stored locally, or accessed remotely via computer networks. These information retrieval systems are able to exchange information with each other through interoperability and sustainability.
The Library of Congress (LOC) is a research library in Washington, D.C., serving as the library and research service for the United States Congress and the de facto national library of the United States. It also administers copyright law through the United States Copyright Office.
The conservation and restoration of books, manuscripts, documents, and ephemera is an activity dedicated to extending the life of items of historical and personal value made primarily from paper, parchment, and leather. When applied to cultural heritage, conservation activities are generally undertaken by a conservator. The primary goal of conservation is to extend the lifespan of the object as well as maintaining its integrity by keeping all additions reversible. Conservation of books and paper involves techniques of bookbinding, restoration, paper chemistry, and other material technologies including preservation and archival techniques.
Helen Diana Burgess, was a Canadian conservation scientist. Burgess spent her career at the Canadian Conservation Institute ("CCI"), where she was a Senior Conservation Scientist. She was a researcher in paper and textiles conservation processes and an expert in the areas of cellulose degradation analysis, conservation bleaching, washing, enzyme applications on paper, as well as aqueous and mass deacidification of paper.
Acidic paper is paper which was manufactured using acidic substances. Widely used since the mid-nineteenth century, its pages become yellow within years, extremely brittle over decades, and eventually unreadable in the library and archive collections intended to perserve them. This process has been called "slow fire".