Alison Trachet: Guest post on the SEAHA conference, 2017

The National Heritage Science Forum (NHSF) provided bursaries to enable three Early Career Researchers to attend the 3rd International Conference on Science and Engineering in Arts, Heritage and Archaeology. Here Alison Trachet shares her experience of the conference.

Last week I traded the daily showers and cloudy skies of north central Florida for the warm, sunny shores of the south English coast to attend the 3rd International SEAHA Conference held in Brighton. SEAHA, which stands for Science and Engineering in Arts Heritage and Archaeology, is a revolutionary academic program training the next generation of heritage scientists. The very name “heritage science” implies collaboration between conservators, historians, and scientists, and thus the emphasis of this conference was on “interdisciplinarity”.

The two-day event began with several warm welcomes and a charge from SEAHA doctoral student Keats Webb to consider what you wanted from the conference and revisit this question after its end. I simply wanted to meet experts and emerging researchers as well as learn current research trends (and possibly hear about post-doctoral research opportunities), yet I experienced so much more. The first keynote speaker, Dr. Robert van Langh, addressed the economic impact of cultural heritage, something I had never considered. Katy Lithgow at The National Trust queried if heritage science is outgrowing interdisciplinary research and becoming its own field. Other fascinating research topics included occupational health and safety issues from pesticides, mechanical testing and characterization of tapestries and ancient Roman glass, and analyzing the smell of potpourri. I particularly enjoyed the budget air velocity measurer developed by Dr. Josep Grau-Bove: a thin strip of paper calibrated to register certain air velocities.

We ended the first day with a private tour of the Royal Pavilion, King George IV’s ornate seaside home.

Image of Royal Pavilion, Brighton
The Royal Pavilion, a famous Brighton landmark and unofficial mascot of the conference.

Despite being sold by the royal family, used as a hospital in World War I, set afire, and crushed by a heavy stone, the Pavilion can still be visited by the public thanks to heroic restoration efforts from a diverse team, making the building a perfect mascot for the conference. After our tour, I wandered about the Brighton museum with a glass of wine, nibbled on delicious appetisers, and chatted with new acquaintances about our professional backgrounds and interest in heritage science. We had the opportunity to individually talk to research presenters during these social events as well as during coffee breaks, the poster session, and at dinner with new colleagues. 

Image of SEAHA conference poster session
Curious conference goers enjoying the poster session

The SEAHA conference was the perfect place for me to catch up on relevant research, network with experts from a wide variety of fields including conservators, scientists, and industry members, and meet the next generation of heritage scientists. I look forward to next year’s conference, where perhaps I can share my own research struggles and results.

Image of seagull
One attendee was very keen on discussing ginger biscuits during a coffee break


The 3rd International SEAHA Conference was held at the University of Brighton, UK from 19-20 June 2017. The Book of Abstracts is available at:

This is heritage science…medieval window glass

In this post, David Dungworth of Historic England explores new ways of looking at decorated medieval window glass. He explains the use of two X-ray based techniques to improve the visibility of the decoration on the glass, traditional X-radiography and a new technique, scanning micro X-ray fluorescence (µXRF).


Coloured, painted and sometimes stained window glass decoration has been a feature of English churches for over a millennium. The ‘atmosphere’ inside a church often depends on the lighting and the decorated windows give daylight rich and varied hues.

While the earliest decorated windows were simple ‘mosaics’ of coloured glass, most later windows were also painted to illustrate scenes from the bible, the lives of saints, royalty, heraldry or benefactors. Some medieval window glass remains in its original windows but most has been moved at least once and much of it has been destroyed.

Medieval window glass has also been found by archaeologists. Although the decoration on some medieval window glass survives well, the glass itself tends to corrode which can make the glass ‘unreadable’. The decoration on a significant proportion of decorated medieval window glass from archaeological excavations is simply not visible.

Hugh Threlfall recently donated a collection of medieval window glass to Historic England which is being used to test a new approach which should improve the ways in which we can view its decoration. The glass (over 1000 fragments) is generally in rather poor condition. Some examples have corroded so much that they are now opaque and the decoration all but invisible (in some cases a layer of mortar appears to have been applied to the decorated surface of the glass).

Imaging the Decorated Glass

We have explored the use of two x-ray based techniques to improve the visibility of this decoration. Traditional X-radiography works well in some cases and we have also begun to use a new technique – scanning micro X-Ray Fluorescence (µXRF). X-ray fluorescence is widely used to discover the chemical composition of materials, by micro-focussing the X-ray beam it can be directed on a tiny spot (0.02mm). By scanning (using a motorised platform) it is possible to scan across the surface of an object. Importantly the paint has a different composition to the underlying glass: it contains high levels of iron and lead. By looking at scans of these two elements we get a picture of the original decoration.

Types of Decoration on the Glass

So far just over 200 fragments have been scanned using µXRF and it is clear that the painted designs on many are closely related. Most were part of the same decorative scheme and so were probably made at the same time and came from the same building (and possibly even the same window). There are a few fragments which have quite different designs. These designs suggest later manufacture (in most cases these fragments are also far less corroded).

Threlfall Glass #0001. A devil from the Torments of Hell? 

Note the yellow was achieved using silver staining which suggests to us that it was manufactured after the beginning of the 14th century.

Most of the glass is painted to produce simple shapes based on leaves or curvilinear geometric shapes (called grisaille). Commonly, some fields are left plain while others, in contrast, are painted with much thinner lines to produce cross-hatching.

A common border comprises a wavy line and dots but this is clearly related to the cross-hatching as at least one fragment of glass has elements of both. This type of grisaille decoration was popular in the first half of the 13th century. Numerous parallels can be found among glass from York Minster, Salisbury Cathedral and Battle Abbey.


A few fragments of glass are decorated with letters, mostly in a font usually described as Lombardic which was commonly used in decorated glass (and manuscripts) until the later 13th century. Careful examination of the lettering suggests that these were produced by two different glass painters. While TG#0010 is well executed, TG#0019 clearly shows how the letter was produced by scraping away paint (before it was fired). TG#0020 contains the letters REX which possibly refer to a king.

Figurative representations are rare but include part of a seated figure (TG#0022) whose right hand is extended with all four fingers straight (ie not a gesture of benediction) suggesting a secular figure (possibly a king). One fragment (TG#0051) comprises part of a face and another (TG#0109) shows the battlements of a castle from a canopy.

The Ian Threlfall Collection and Alcester Abbey

Hugh’s father (R Ian Threlfall) had been a barrister who, in the middle of the 20th century, helped archaeologically excavate a number of medieval sites (usually with Martyn Jope). Ian found numerous archaeological artefacts when sorting out the family home. He managed to work out where most of them had come from and donate them to the appropriate museum; however, there was a large collection of medieval window glass with no information about its origin. A thorough search through Historic England Archives revealed that R Threlfall was the director of archaeological excavations by the Birmingham Archaeological Society at a Benedictine monastery at Alcester Abbey in 1938. The abbey was founded in the late 1130s but went into decline in the 14th century, had become a cell of Evesham Abbey in 1465 and was dissolved in 1540.

R I threlfall QC
Ian Threlfall

Five minutes with…Keats Webb, PhD student, SEAHA; Digital Imaging Specialist, Smithsonian Museum Conservation Institute

What’s your background in heritage science?

I have been doing scientific and computational imaging for research and conservation documentation of the Smithsonian collections at the Museum Conservation Institute (MCI) for five years. I have a background in fine art photography and was trained on-site by a senior conservator turned imaging specialist in the specific techniques and applications within conservation.

I use a range of techniques including multispectral and hyperspectral imaging, photogrammetry and 3D scanning, digital radiography and reflectance transformation imaging (RTI).

In the autumn, I started a heritage science program for the Science & Engineering Arts Heritage & Archaeology (SEAHA). SEAHA is a Centre for Doctoral Training (CDT) funded by the Engineering & Physical Science Research Council (EPSRC) created by University College London, University of Brighton and University of Oxford.

What’s you role at SEAHA and MCI?

As a student I am researching the spectral and 3D imaging techniques for object documentation and the eventual integration of the techniques.

As a digital imaging specialist, I am working with a range of scientific and computational imaging techniques to answer research and conservation questions about objects and collections coming from conservators, curators and researchers.

Keats Webb 3D scanning a test object (a ceramic figure from Senegal) as part of her research with the Cultural Informatics Research Group at the University of Brighton.


What’s been the most exciting/challenging thing you’ve worked on recently?

Part of my research has involved a case study imaging collection items from the Freud Museum in London, UK. The Museum is Freud’s last residence where he moved in 1938 to flee from the Nazi’s in Austria. After Freud passed away in 1939, his daughter lived in the house for another forty years and the Museum opened in 1986. The collection is a combination of libraries, archives and about 2000 antiquities (Roman, Greek, Egyptian and Oriental). Freud was very interested in archaeology and antiquities and used archaeology as a metaphor for psychoanalysis. It was quite exciting to be working in Freud’s study and to be able to image a wide range of objects of different materials and origins.

Keats web
Keats imaging a white ground lekythos (#4492) at the Freud Museum.


Who inspires you?

In 2009, I was taken on as an intern by MCI Senior Furniture Conservator, Melvin Wachowiak. Mel was a Senior Furniture Conservator turned imaging specialist with an enthusiasm and passion for conservation and new technologies. Mel was very generous with sharing his knowledge and expertise and he was dedicated to mentoring and training others. I had the privilege of having Mel as a mentor for nearly five years. He was very thoughtful and meticulous in his work, he valued collaboration, he was enthusiastic about the process and results, and he had a priority for accessible techniques that maintained innovation.  Mel passed away in May 2014, but I still find him to be an inspiration for the work that I do and will continue to do.

What do you love most about your job?

I absolutely love my work as an imaging specialist at MCI!! MCI does not have a collection, but supports the 19 Smithsonian museums and galleries in addition to the research facilities. This allows me to work with a range of collections and materials, which makes the work  interesting and exciting. I have had the opportunity to work on paintings, mummies, musical instruments, fossils, just about anything you can imagine in a museum collection.

As a student, I have had an incredible opportunity to expand my skill set and focus on my research abilities while working on different collections and making new contacts. I enjoy meeting other heritage professionals that are excited and interested about cultural heritage imaging, and the SEAHA program has allowed me to expand my network into the EU.

In a single sentence, tell us what’s great about heritage science?

The interdisciplinary nature of the field and the ability to use science to learn more about our heritage makes heritage science really exciting and great!


Find out more about SEAHA and its work at

A brief theory of heritage science by Professor Matija Strlic, UCL Institute for Sustainable Heritage

Premise 1: In one way or another, we have been doing heritage science for ages. I will use this term to describe the science of heritage, i.e. how we manage, interpret, conserve heritage as well as provide access to it [1]. In his lecture at the Royal Institution in 1843, Michael Faraday lectured about pollution importantly contributing to book degradation. A bit of poignant trivia: Faraday was trained as a bookbinder before he became one of the most influential scientists of all times.

Red rot on leather: one of the first topics to excite heritage scientists.


Premise 2: Heritage science is culturally dependent. The fact that ‘heritage’ is a culturally dependant term gives our field of scientific enquiry an interesting angle: the value (or, retrospectively, ‘impact’) of the science that we do depends on the culture we inhabit. Research on a 1970s piece of plastic furniture could be exciting in the context of a design museum and completely rubbish in the context of a society in which such objects do not have ‘cult’ status. I use the term deliberately.

Purchased in a flea market as rubbish, valuable as a scientific sample.


Premise 3: Heritage science is inherently biased. If heritage is stuff (tangible or intangible, material or digital) with cult status, don’t scientists, by doing research on it, contribute to its glorification? The heritage value of an object could well be its scientific interest – which makes the science that we do inherently biased, because by studying an object we implicitly contribute to its status. Dolly the sheep at the National Museum of Scotland is a case in point.[2]

Scientists create heritage through their research.


Premise 4: Heritage science can be neither fundamental nor experimental. While in the use of mock or surrogate objects for research, the experimental approach principles typical of scientific endeavour are embedded, science of heritage cannot be repeatable because heritage is not an experiment. Equally, there can be no fundamental research question because the objective of heritage science is always known.

As heritage is not repeatable, is heritage science experimental science?


Premise 5: Heritage science is multivariate. This is not to say that it is not exact science; however, since the context of heritage can be unknown, there can be any number of variables affecting the heritage system under observation – in this, the premise of heritage science comes close to social science, although the ‘society’ we study is a population of ‘things’ – with their individual lifetimes and dynamics of change and interactions (all culturally dependant, of course).

They look the same, move the same, feel the same, but are not identical.


Premise 6: Heritage science helps to interpret heritage. The heritage value of an object is in the benefits we obtain from interaction with it, not in its (material) representation (unless we believe that an object has value in and of itself). Through our senses, we interpret them and extract information from them. This metadata can become more valuable than the item itself; a study of the value of mineral collections has shown that curators may well value the metadata more than the objects.[3] The market value of this metadata can easily be immeasurable.[4]

Metadata: not just any snack, this one was in space!


Premise 7: Heritage science provides evidence for sustainable conservation. Keeping stuff for longer is inherently sustainable, but can keeping it for too long (the society has a view on what is acceptable) become an unsustainable proposition?[5]  How do we balance our need to own, with our needs to breathe and eat? We need evidence to provide balance. I risk sounding Darwinian when I say that when time has its way with heritage, it can be for the better.

Long-term storage: how long is too long?


Premise 8: Through improved access, heritage science contributes to well-being. Heritage that is accessible, in its preserved authentic form or as a (digital) reproduction, is a “resource for economic growth, employment and social cohesion”[6]. Quite how we should balance the extraction of economic or social benefits from the heritage resource with its preservation is an open question of heritage resource management and the science supporting it.

Digitisation: increased benefits from access to heritage.


Premise 9: Heritage science is proof that there is no world of Two Cultures [7].  A scientist, researching heritage defies the existence of the divide: there can be no scientific research of heritage without a contribution by humanities research. Heritage science also successfully bridges science and culture, because it provides an attractive vehicle to convey ideas and concepts related to technology and engineering, as well as culture and society.

Engaging with heritage and with science: there is no disciplinary gap.


Premise 10: Heritage science urgently needs to develop its identity. It yet needs to populate a defined space; it needs a voice to represent researchers; it needs a unifying theory; it needs to define its grand challenges.

Matija Strlic, UCL Institute for Sustainable Heritage




[3] J. Robb, C. Dillon, M. Rumsey, M. Strlic: “Quantitative Assessment of Perceived Value of Geological Collections by ‘Experts’ for Improved Collections Management”, Geol. Cur., 9 (2013) 529-543


[5] C. Dillon, W. Lindsay, J. Taylor, K. Fouseki, N. Bell, M. Strlic: “Collections demography: stakeholders’ views on the lifetime of collections”, Climate for Collections Conference, Munich, Doerner Institut, 7-9 November 2012, Postprints, J. Ashley-Smith, A. Burmester, M. Eibl (Eds.), Archetype, London, 2013, pp. 45-58.



Five minutes with…Cathy Tyers, Dendrochronologist, Historic England

What’s your background in heritage science?

Having completed a degree in Applied Biology I was offered a 4 month contract, funded by English Heritage, in the Archaeology Department at Sheffield University working in the dendrochronology (tree-ring dating) laboratory. I spent the next 28 years working in the laboratory on timbers from all over England from archaeological sites and historic buildings, and other wooden objects (logboats, chests, staircases, panelling, and even a totem pole!), as well as living trees. In 2012 I transferred from the university to work directly for English Heritage/Historic England.

What’s you role at Historic England?

I’m part of the Scientific Dating team and as a dendrochronologist I work with people right across both Historic England and the English Heritage Trust, as well as all sorts of people outside of these organisations, such as archaeologists, building historians, conservation officers, historic interest groups, and of course other dendrochronologists and heritage scientists. My role is to help understand the wealth of historic buildings and archaeological remains that we’re so lucky to have. One day I can be working with living trees to understand more about landscape gardens associated with some of our stately homes, another day I can be working on a roof in an apparently anonymous historic building that proves to be 14th century and hence suddenly very important, and the next providing a date for a timber structure that proves to be over 4000 years old.

Old Hall Farmhouse
Old Hall Farmhouse, Brightholmlee, Bradfield, near Sheffield. We were able to determine that the timbers were felled over 500 years ago, in 1484. Photograph by kind permission of Alison Arnold. © Alison Arnold


What’s been the most exciting/challenging thing you’ve worked on recently?

I’m currently involved in the dendrochronological component of a project investigating historic buildings in Beverley in Yorkshire. The project is being undertaken by the Yorkshire Vernacular Buildings Study Group ( with funding from Historic England. From a dendro point of view the work is proving somewhat challenging (and therefore most definitely fun) – this is an area of the country where surprisingly little previous work has been done and what has been done has shown that the trees used in the buildings are not behaving as they should do, making our job of dating them difficult! Having failed to date one of the buildings, with an impressive crown post roof and thought to be over 500 years old, by dendrochronology we’re now going to involve other heritage scientists and use another scientific dating technique so that the YVBSG does get a date for this building to include in their account about the early development of Beverley. I’m also very much hoping that all of this dendro work will tell us about the medieval woodlands that surrounded Beverley some 400-500 years ago that were used to produce the building timbers still visible in the town.

Who inspires you?

From a purely work perspective the people I gain most inspiration from are those members of specialist historical interest groups, like the YVBSG, who do so much investigative work in their own time and yet they provide the basis for so many of the fascinating projects that we as heritage scientists have the opportunity of being involved in.

What do you love most about your job?

I love the fact that I never really know from week to week what I’m going to be doing next or who I’m going to be talking to. I love the excitement of being able to show that the timbers in a roof of a building in a tiny hamlet near Sheffield were felled over 500 years ago in AD 1484; that the timbers excavated from a sunken wreck were used in the ship’s construction in AD 1628; and that a board from a 17th century panel painting on display at Kenwood House was imported from woodlands in the eastern Baltic. Basically never a dull moment!


View of Old London Bridge
View of Old London Bridge, by Claude de Jongh. The wood of this 17th century panel painting from Kenwood House was imported from woodlands in the Eastern Baltic. © English Heritage


In a single sentence, tell us what’s great about heritage science?

Heritage science has the ability to reveal amazing details about what people did and when, how they lived and what happened to them.


Five minutes with…Dr Lora Angelova, Newton International Fellow, University College London

What’s your background in heritage science?

I obtained a PhD in chemistry from Georgetown University, but focused my research on heritage science by having joint supervisors – professor of chemistry Richard Weiss at the university, and heritage scientist Barbara Berrie at the National Gallery of Art, Washington, D.C. The focus of my work is to develop and study gel cleaning systems used in conservation treatments. Gels are sometimes used during the surface cleaning of a myriad of heritage objects (paintings, frames, sculptures, even paper). The idea is that by holding the cleaning liquid in a thick gel, the cleaning action can be more ‘controlled’, i.e. the liquid is less likely to penetrate into the artwork, or spread and drip on the surface (if the artwork is vertical). Gels can also be used to reduce the risks posed by rubbing a sensitive surface with a cottons swab during cleaning (for example, on gold leaf decorated frames), and to clean hard to reach places, like crevices beneath paint impasto.

What’s your role at the Materials Studies Laboratory at UCL?

I am in the second year of my Newton Fellowship (a postdoctoral fellowship awarded by the Royal Society to external researchers who would like to work in the UK). I work with Emma Richardson in a laboratory on the top floor of the History of Art Department – we are the only scientists in the department! It’s a very different environment from working in a chemistry lab, and I really love it.

There are a few instruments here, but the one I am primarily using in my research is called an NMR MOUSE (Nuclear Magnetic Resonance, Mobile Universal Surface Explorer). The instrument allows me to look into paint films, and trace how liquids from different types of gel cleaning systems move into the paint. I am studying several gels which are used by conservators and hoping to clarify how much ‘control’ of the cleaning liquid they actually present, relative to just using a cotton swab wetted with the cleaning liquid.

The NMR MoUSE (the tiny black box on the blue platform), in the process of scanning a paint-out which has just been treated with a gel.


What’s been the most exciting/challenging thing you’ve worked on recently?

Last year I worked with a conservator who was treating a painting which had been largely overpainted centuries after its production. The overpaint film was very stiff and had extensive craquelure – when he tried to soften the overpaint with a wetted cotton swab, the cleaning liquid would be drawn through the cracks into the original, sensitive paint layer beneath. We were hoping that by using a gel, we could slow this process, and soften and remove just the tough, top layer of overpaint. Although the gel did allow some control and prolonged exposure of the overpaint to the cleaning liquid, it was not sufficient to soften it without having some of the liquid penetrate through the cracks to the original paint beneath! The treatment was incredibly challenging, and the conservator opted to use a gel on some areas and cotton swabs on others.

Applying a fluorescent gel to a test-panel during my PhD – the fluorescent solvent can help us trace its penetration into the paint.


Who inspires you?

I really admire competitive and determined people who are passionate about what they do, both in their professional work and in their hobbies, especially if they’re women.

What do you love most about your job?

I get to combine the two things I was always most interested in as a child – science and art. I can make paint-outs in the morning and study their chemistry in the afternoon. I can look at the topography of a painting through a microscope – which feels almost like looking at the surface of the moon to me. Being a scientist can be demanding, of course, but as an academic, I get to choose what research I pursue, at what time I come in and leave work, and what the radio is playing in the lab. To top it off, I get to work with a very diverse group of people – conservators, art historians, artists, and scientists from a very wide range of disciplines.

In a single sentence, tell us what’s great about heritage science.

There is an inexhaustible supply of fascinating questions and problems to explore, and there is always a clear application which makes my work feel really worthwhile.

Five minutes with..Mark Kearney, ICON/HLF Intern (conservation of modern materials), Victoria & Albert Museum

What’s your background in heritage science?

My scientific background comes from my undergraduate degree. I have a BA(Hons) degree in Physics with Astrophysics; by the time I was in 4th year I knew I wanted to push my career into a different context. A professor, who works with Raman spectroscopy, told us about the work he was doing analysing pigments used in the Book of Kells. That short talk really grabbed my imagination so after graduating I did a Graduate Diploma in Conservation followed by an MSc in Professional Conservation. The studies I did after my undergraduate really helped me to understand the needs of the heritage industry (ethics, conservation materials & treatments, and the types of objects found in collections.) It was during my MSc I really started to develop my heritage science experience. I found that I was using the same techniques and theories I used in my undergraduate but instead of exploring new materials I was trying to understand heritage ones – the science was still the same though.

What’s your role at the V&A?

I work in the Conservation Science department alongside a number of other scientists whose backgrounds are in chemistry and physics. The department offers a range of analytical techniques to the museum like micro FTIR, Raman and micro XRF as well as advice on lighting and environmental conditions, pest management, and potential issues with new acquisitions. We work closely with curators and conservators advising them on the materials and techniques used within objects. We also carry out research into new conservation methods and materials so that the bench conservators have a solid scientific backing for their treatments. This is the type of work I’m currently undertaking – my internship is focused on looking at how best to clean modern materials. Plastic objects are surprisingly vulnerable and tricky to clean without damaging them. I am critically assessing how and with what we clean different plastics.

cleaning foamed polystyrene
The result of trying to ‘clean’ foamed polystyrene with acetone. Th acetone eats away at the plastic surface.© V&A


What’s been the most exciting/challenging thing you’ve worked on recently?

The most challenging thing I’ve worked on was taking some varnish samples from a Medal Cabinet that the museum had just acquired. The furniture conservator wanted to know if any modern varnish had been used in previous treatments of the object so together we removed some small samples from the surface using a scalpel. Training for sample removal on teaching collections isn’t exactly the same as the real thing; so when you’re faced with an object that is not only expensive but has been deemed so significant the government halts its export sale you can get a little nervous. But you trust your training and yourself. I’m really looking forward to coming back to the museum a few years down the line and being able to say I helped with that object.

Image One
A sample under magnification being prepared for FTIR analysis. The red substance is burned sienna, the glassy is amber.© V&A


Who inspires you?

I don’t really have a person who inspires me – really what makes me want to continue in heritage science are the objects (as utterly corny as that is to say!) I really enjoy researching objects, seeing how they were made, how they are degrading and how we can help keep them around for as long as possible.

What do you love most about your job?

How different each day can be. I get to interact with lots of different curators and conservators who have a great love of heritage and the institutional knowledge means you learn something new all the time. Physicists are  naturally inquisitive and creative and heritage science gives us a really novel way to apply our problem solving skills with the creativity of art and design.

In a single sentence, tell us what’s great bout heritage science.

Everything – rigorous science, fascinating objects, mentally challenging yet rewarding work, and something different every day –  what’s not to like?