Background: The permanence of paper used in printed documents and books has long been a concern for archivists and librarians. Research studies using accelerated aging techniques had shown that paper degraded differently when it was exposed to different elevated temperature and humidity conditions, and whether it was exposed as single sheets or in stacks. In order to be able to make accurate predictions about the behavior of a particular type of paper over the long-term it is important to know whether, and under which conditions, accelerated aging most closely simulates natural aging. To investigate the ability of artificial aging techniques to mimic the real-time degradation of paper objects it is necessary to compare the changes that occur in physical and chemical properties observed at elevated conditions to those occurring in naturally aged papers.
From 1994 to 2000 the American Society for Testing and Materials (ASTM) and its Institute for Standards Research (ISR) administered a multi-institutional research program designed to develop new accelerated aging test methods that could be used to model the natural aging of any type of printing and writing paper. Fifteen printing and writing papers were custom-made for the study with compositions ranging from 100% cotton to high-lignin, and from acidic to alkaline. The accelerated aging studies addressed the effects of several environmental parameters on the aging of the papers: temperature and relative humidity (RH); light; and nitric oxide (NO2), sulfur dioxide (SO2), and ozone (O3). At the end of the project a new accelerated aging technique using paper sealed in air-tight glass tubes was written, and approved as ASTM Test Method D6819 in 2002.
Historic papers of known dates were also studied as part of this research project, providing model chemical fingerprints of naturally aged papers. However, as their original composition and subsequent storage history are unknown, differences observed among the historic samples are difficult to interpret. As there had never been a set of well-characterized papers set aside for a very long time under monitored and controlled conditions, there was no data available to determine a formal correlation between accelerated and natural aging experiences. Sponsors and research participants of the original study engaged a group of ten institutions that were willing to store a set of the same papers used in the accelerated aging research for 100 years, and four research laboratories that would periodically test the papers and collect data on the environmental conditions under which the papers were being stored. “The Long-Term Natural Aging of Printing and Writing Papers” project began in 2000.
Contributing Studies: Shahani, C.J.; Lee, S.B.; Hengemihle, F.H.; Harrison, G; Song, P.; Sierra, M.L.; Ryan, C.C.; Weberg, N. Accelerated aging of paper: I: Chemical analysis of degradation products, II: Application of Arrhenius relationship, III: Proposal for a new accelerated aging test. Preservation Research and Testing Division, Library of Congress, Washington, DC; June 2000.
Arnold, Bruce. ASTM Paper Aging Research Program The Book and Paper Group Annual, Vol.19. Washington, DC: American Institute for Conservation Book and Paper Group. 2001.
Shahani, Chandru. "Accelerated Aging of Paper: Can It Really Foretell the Permanence of Paper." Proceedings from the ASTM/ISR Workshop on the Effects of Aging on Printing and Writing Papers. Philadelphia, PA July 1994. [PDF: 326 KB / 18 p]
Aging: Improved Accelerated Aging Testing Techniques
Arnold, R. Bruce; Chair: ASTM Paper Aging Research Program; R. B. Arnold Associates, Inc. ASTM's Paper Aging Research Program. cool.conservation-us.org. 23 November 2008.
Project Description: The objective of this multi-institutional collaborative project is to store sets of custom-made, 20th century printing and writing papers at different libraries/archives, monitor the environmental conditions, and conduct physical and chemical analyses of the papers over a 100-year period from 2000 to 2098.
The current role of the Library of Congress (LC) is to coordinate data collection from all participating institutions, and participate in the Program as one of the designated testing laboratories.. This includes collecting the data for the storage environments for the test papers; sending annual notices to all libraries/archives to complete the environmental data sheets; and conducting fold endurance tests of all samples, analyzing the data; and storing un-tested samples of all papers from the study, including the original ISR test papers, for long-term reference.
The 15 papers are stored in 10 different libraries/archives in which the temperature and RH, artificial lighting, and levels of NO2, SO2, O3, and acetic acid (as funds permit) are recorded. Storage environment data is compiled and collected annually, and paper samples are sent for chemical and physical testing at the following intervals: 2000, 2003, 2008, 2013, 2018, 2028, 2038, 2058, 2078, and 2098.
Outcomes/Findings: This is a 100-year project in which the cumulative data acquired over the course of the project will be compared to the data from the accelerated aging experiments conducted in the original ASTM/ISR project at the end of the 100 years. To date, the Library has completed the required fold tests of all papers for years 2000, 2003, 2008, and 2013, and has collected test data from the other participating laboratories for the other specified analyses. Changes in leadership and oversight of this program at the participating institutions and laboratories present a challenge to the continuity of such a large and complex long-term collaborative endeavor, and to facilitate sustainability, the Library has taken a leadership role in coordinating and collating data.
Acknowledgements: The Library acknowledges the three other collaborative research laboratories at the following institutes: Canadian Conservation Institute (Canada), Rochester Institute of Technology/Image Permanence Institute (USA), and the USDA Forest Service Forest Products Laboratory (USA). We also acknowledge the 10 libraries/ archives where the papers are stored: Arizona State University (USA), Canadian Conservation Institute (Canada), Columbia University (USA), National Archives and Records Administration (USA), National Library of Medicine (USA), University of British Columbia (Canada), University of California-Berkeley (USA), University of Florida (USA), The University of Texas at Austin (USA), and Washington University (USA).
Update and Images:
Image of fold endurance testing of paper, TAPPI T511 test method
January 2011: All un-tested papers collected from the 10 institutions in 2000, 2003, 2008, and 2013 are being kept in refrigerated dark storage, along with one ream of each of the fifteen papers that have been stored since the start of the study to establish a base condition for future research. The remaining un-tested ISR papers have been transferred to the Center for the Library's Analytical Scientific Samples (CLASS) as part of the reference sample collections stored therein.
January 2013: To date, the Library has received samples from all ten institutions for each of the sampling periods, environmental storage condition data for all years of the study from two of the participating institutions, and partial environmental data from the other institutions.
