A multidisciplinary team from the University of St Andrews’ Libraries & Museums and the Schools of Earth Sciences and Physics and Astronomy have developed a tool to test bookbindings for the presence of emerald green pigment.
The tool is hand-held and uses wavelengths of visible and infrared light shone onto the sample for under a second. The instantaneous test result is displayed on device and indicates whether emerald green pigment has been detected or not. The false-negative rate is null and the false-positive rate is 15%, so that no emerald green coloured books test as being safe.
The Project
Following the University of Delaware’s Poison Book Project, in 2022 University Collection staff began working towards quantifying the risk in the rare book collections with the longer-term aim of targeted mitigating measures. A merger between the Library and Museum at the time brought about an increased awareness of hazards which along with the wide publicity of the Poison Book Project facilitated institutional support. The challenges however were two-fold – identifying 19th century green bindings which should be tested and obtaining a means to detect the compounds of emerald green pigment.
Using the date range for emerald green production and binding descriptions as parameters, a catalogue search resulted in the overwhelming figure of over 100,000 books. Inspection of volumes at the shelf confirmed the complexity of the issue beyond just green coloured book cloth as green papers, parchment, inlays and onlays, edge decoration, endpapers andwaste papers were revealed.
Exploratory at shelf testing using non-destructive visible and near-infrared spectroscopy equipment, used by geologists to identify minerals, led to the recognition of emerald green’s unique reflectance pattern in visible light by Heritage Scientist Dr Pilar Gil. This work has been published in Analytical Methods volume 15, number 47 in December 2023.
The overwhelming number of collection books still to be tested, along with steady requests from colleagues to test further books was coupled with limited resources. The University Collections team quickly switched course to developing a tool based on emerald green’s fingerprint spectral pattern; thereby enabling colleagues, and ultimately the wider sector, to detect emerald green in bindings.
Collaboration
The most recent tranche of physics-sector funding has enabled a prototype tool to be developed and tested in several collaborating institutions within Scotland’s central belt. Second year product design students at the University of Dundee’s Duncan of Jordanstone College of Art and Design have advanced the design of the hand-held tool casing.
Seeking notes of interest
A run of tools will be produced in the second half of 2025 and distributed – for the cost of production - to institutions, collectors and sector-professionals who have expressed an interest.
To register your interest, please contact the team at [email protected].
Erica Kotze ACR