At the Heritage Science Laboratory Ljubljana, a substantial research collection of historic paper is available to researchers through E-RIHS.si. The collection was assembled and fully characterised in the EU research project SurveNIR, coordinated by professor Matija Strlic.
Through the use of a number of multivariate data visualisation and analysis tools, it was shown that acidity of paper in its current state of degradation is not only a consequence of alum-rosin sizing but a complex variable closely related to degradation of cellulose and possibly rosin and lignin. The average rate of acid catalysed hydrolysis of cellulose in papers from 1850 to 1990 was shown to be 10−5 year−1, which appears to be closely associated with the accumulation of carbonyl groups. Questions emerged related to degradation of rosin and lignin, specifically to their contribution to carbonyl group content and acidity which has so far been largely overlooked in the literature.
This research demonstrates the extraordinary value of chemical characterisation of a significant number of historic samples in the studies of their composition and degradation.
The paper was co-authored with colleagues from UCL Institute for Sustainable Heritage, Smithsonian’s Museum Conservation Institute, Lichtblau e.K., Dutch National Archives, The British Library, Swedish National Archives, and University of Bristol.