In our final May posting from the SEAHA cohort, Natalie Brown describes her research to develop a simple, non-destructive method for assessing the ‘health’ of paper-based collections that can be carried out as part of daily operations.
Natalie will be chairing one of the sessions at the 2nd International SEAHA conference which is being held in Oxford, UK 20th-21st June. The conference explores heritage science from many angles, including sessions on policy and management, imaging, environments, analytics, novel techniques and conservation techniques. For further information, including the full programme and how to book see: www.seaha-cdt.ac.uk/seaha-conference-2016/
Collection Surveys as Part of Library Document Supply Chain
By Natalie Brown, UCL Institute for Sustainable Heritage
Matija Strlic, UCL Institute for Sustainable Heritage
Tom Fearn, UCL Department of Statistical Science
Dirk Lichtblau, Lichtblau e.K. www.lichtblau-germany.com/
David Howell, Bodleian Library www.bodleian.ox.ac.uk/bodley
Fenella France, Library of Congress http://www.loc.gov/preservation/scientists/
Memory institutions, such as libraries and archives offer a unique, multi-faceted service to the public. They are centres of lifelong learning that foster tangible links to the past by enabling access to information. Within these institutions preservation measures are set out to ensure the prolonged life of paper collections, often focusing on the ‘health’, or the overall condition of the collection relating to its usability. To understand the overall condition of a paper object, several chemical and physical parameters are considered including acidity, lignin content, additives in the paper, the sizing and tensile strength. Through my research I aim to create a straightforward and non-destructive method for library staff to assess and understand the ‘health’ and deterioration of their collections, integrated into the daily library operation.
Within institutions, gathering data on their collection’s ‘health’ is an important preservation measure; however, it requires surveys that can often be resource-intensive and rely on the sensory judgment of experts or even semi-destructive tests. As non-destructive testing advances, spectroscopy has become an attractive alternative, where the chemical and physical parameters important for preservation can be analysed quickly and without causing physical change to the object. My project specifically uses near infrared-spectroscopy (NIR), a method that uses the near-infrared region of the electromagnetic spectrum, with the assistance of multivariate chemometrics to help interpret the complex spectra of the object (Fig. 1).
Figure 1. The NIR spectrum of a European rag paper (pink) and NIR spectrum Chinese Xuan paper (blue). Although the papers are very different, their spectra look almost identical.
Past research in this area has predominantly focused on the characterization of Western papers. A user friendly instrument, SurveNIR (www.science4heritage.org/survenir/), has been developed by the project’s industrial partner Lichtblau e.K. (Dresden, Germany). SurveNIR is able to characterize 15 paper properties important for preservation. The first stage of this project has been to build on the previous research and extend the application of NIR technology, developing models to analyze different Asian papers. Laboratory tests were performed on a reference collection of 200 19th and 20th Century Chinese papers and several NIR applications were successfully developed for these papers including pH, degree of polymerization, tensile strength, lignin content, and dating. Working closely with Lichtblau e.K. it is the hope that in the future I will be able to develop NIR applications for other Asian papers.
Figure 2. Two samples of 19th Century Chinese handmade paper that were used to create NIR models.
In the second phase of the project I will be working closely with two heritage partners; the Bodleian Libraries, the University of Oxford and the Library of Congress, (Washington D.C.). During this time, NIR tools will be used to conduct mass condition surveys on real library collections. By working within these institutions I can investigate the needs of practitioners and identify specific technology deployment challenges to develop a methodology that implements these tools. As the technology is highly accessible there is scope for several stakeholders to engage with the project, including book fetchers, conservators, curators, and institutional visitors.
Figure 3. Natalie using SurveNIR to analyse European paper samples © D. Lichtblau
The final stage of this project will be data analysis. A huge amount of data will be collected while working at the case study libraries, and thousands of books of characterised. The information gathered could feed into future risk assessment, trend predictions, and prevention of accelerated deterioration due to the environment. From this, the life expectancy of collections can be assessed more easily, stricter preventative measures can be implemented where needed and environmental parameters can be loosened.