By Lucia Burgio on behalf of the Heritage Science Expert Working Group

If you have visited a conservation science laboratory before – whether a private enterprise or a facility within a museum or a heritage collection – you will have noticed many different types of scientific equipment used to analyse objects or address specific conservation questions. In cultural heritage, scientists may know how best to use their equipment and how to interpret the resulting data, while curators and conservators may have specific problems or questions. The challenge: it is not always straightforward to find a shared language and meet on a common ground. And it is not unusual for scientists to be seen as too technical, too abstract, too ‘scientific’.

Building this bridge is one of the purposes of the Expert Working Group for Heritage Science (HS-EWG), which was established a few years ago within the Analytical Methods Committee of the Royal Society of Chemistry. One of the aims of this group is to explain in relatively simple, non-specialist terms which analytical techniques can be used to address specific cultural heritage issues.

One of the ways we do this is by producing so-called technical briefs, each discussing individual scientific techniques or their applications to specific materials or types of objects. These briefs are relatively short (usually around 2,000 words) and  available free of charge from the HS-EWG’s web page. They can also be found on the website of Analytical Methods, an open-access scientific journal published by the Royal Society of Chemistry. 

How do we choose the topics for our technical briefs? Sometimes we are approached by scientists who volunteer to write a brief on a specific topic for us, but most often we simply pick each other’s brains and select an issue that is interesting and topical. The EWG includes a variety of professionals: conservators, scientists who work with collections in museums or in other cultural heritage institutions, and scientists who work in academia. Each of us has our own area of expertise in cultural heritage. Do you want to know how porcelain can be analysed and even dated using X-ray fluorescence (XRF)? There’s a technical brief that explains just that. Have you ever wondered what Raman microscopy is really good for, and what types of lasers and experimental conditions are best for your particular object? We produced a technical brief for that too (Figure 2).

The briefs’ topics are wide-ranging, and include FTIR of modern materials, a background paper on micro-computed tomography, an introduction to analytical pyrolysis, and more (see Table 1 for details on how the briefs apply to book and paper issues). There are also a number of new briefs in the pipeline, which are being worked on right now and will be published over the next few months (see Table 2).

Table 1 – Published technical briefs (TB)

TB number and date of publication	TB topic	Main applications to books and paper
No 66 – February 2015	Heritage Science – an introduction
No 67 – May 2015	Raman spectroscopy in cultural heritage: Background paper	Identification of pigments Investigation of pigment degradation Help in dating/authenticating/provenancing
No 75 – July 2016	UV-visible-NIR reflectance spectrophotometry in cultural heritage: Background paper	Characterisation of paper, parchment, pigments and dyes Help in dating/authenticating/provenancing
No 77 – March 2017	X-ray fluorescence (XRF) analysis of porcelain: Background paper	N/A
No 80 – July 2017	Surface-enhanced Raman spectroscopy (SERS) in cultural heritage	Identification of dyes Investigation of dye degradation Help in dating/authenticating/provenancing
No 83 – January 2018	Identification of plastics in cultural heritage collections by Fourier transform infrared spectroscopy (FTIR)	Identification of modern materials in paper and books
No. 85 – October 2018	Analytical pyrolysis in cultural heritage	Analysis of resins, lacquers, proteins, polysaccharides, oils; Analysis of modern synthetic polymers Assessment of wood degradation
No. 91 – September 2019	Laser-induced breakdown spectroscopy (LIBS) in cultural heritage	Micro-destructive, elemental analysis of substrates, pigments and other materials
No. 98 – August 2020	X-ray micro computed tomography in cultural heritage	3D virtual reconstruction of objects Structure and repairs Wax seals Investigation of the binding, hidden features and invisible structural weaknesses Distribution of heavy elements (mercury, lead, etc.) Virtual unrolling of scrolls
No. 101 – January 2021	Analysis of historical dyes on heritage objects	Identification of organic dyes

As it happens, many of us have a special interest in paper and books, which means that these types of objects and their investigation are never too far from our minds when we commission and curate the technical briefs. We are currently putting together briefs on multispectral imaging – a technique which is particularly suited to investigating underdrawings and hidden features in manuscripts. We are also working on a brief on microfading, one on colourimetry, etc. (see Table 2).

Table 2 – Technical briefs in the pipeline

Upcoming TB topic	Main applications to books and paper
Introduction to neutron techniques	Investigation of objects’ structure
Historical wax analysis	Characterisation of wax components on objects Investigation of seals and coatings
FTIR of archaeological organics	Investigation of archaeological wood, parchment, paper, bone
μCT of built heritage	N/A
Microfading	Investigation of lightfastness of dyes
Digital microscopy	High magnification imaging Investigation of tool marks and watermarks
Colourimetry	Monitoring of chromatic alterations on objects
Multispectral imaging	Revealing underdrawings Mapping retouchings, pentimenti and restorations

We also organise or take part in events that help to disseminate the same type of information we publish in the technical briefs, and to promote awareness of analytical science applied to heritage issues. The last such event was the Theobald Lecture at the Victoria and Albert Museum in February 2020, before we all went into our very first COVID-19 lockdown.

Do have a look at the technical briefs that have already been published, and if you have a specific topic you would like to see covered, please get in touch through science@rsc.org!

Dr Lucia Burgio is senior scientist (object analysis) at the Victoria and Albert Museum, London. She graduated in Chemistry summa cum laude from the University of Palermo, Italy, and completed a PhD in Chemistry at University College London. After a few months working in Italy, she joined the Science Section, Conservation Department, at the V&A in 2000. Her main duties involve the scientific analysis and technical examination of museum objects. She assists the Museum’s curators and conservators with the examination and understanding of the objects, and also with their dating, provenancing, attribution and authentication. She is a Fellow of the Royal Society of Chemistry, has been an Honorary Research Fellow at UCL since 2001 and has been chairing the AMC Heritage Science Expert Working Group, Royal Society of Chemistry, since 2014. Her main interests include pigments and artists’ materials, as well as oriental lacquer.