Polychromy Revealed: from medieval wood craftsmanship to 3D printing (Paola Ricciardi)

The next post in our British Science Week 2018 series is by guest writer Paola Ricciardi. Paola Ricciardi is the Research Scientist at the Fitzwilliam Museum in Cambridge. She specialises in the non-invasive analysis of polychromy (multi-coloured painting) in cultural heritage objects. In this blog, Paola talks about a workshop on digital imaging, modelling, making and interpretation of 3D cultural heritage objects and their replicas.

The Fitzwilliam Museum holds a small but exceptional collection of medieval wood sculptures, largely polychrome, made across Western Europe c.1300-1550. For the most part extremely fragile, most of the sculptures have never been exhibited and are largely unknown to the public and to academics. Following a 10-month pilot project in 2017, we are currently running a series of activities funded by the Arts and Humanities Impact Fund of the University of Cambridge. These activities are aimed at maximising the impact of the pilot and at defining routes to impact for a large-scale research project – POLYCHROMY REVEALED – which will enable us to investigate, interpret, conserve and display the collection, ultimately transforming it into a resource that can be utilised for teaching, research and public engagement.

Picture of pair of kneeling angels. Copyright Fitzwilliam Museum, Cambridge
Pair of Kneeling Angels, Northern Italy?, 15th Century. Image copyright – The Fitzwilliam Museum, Cambridge.

Three events, running in March-May 2018, are particularly aimed at opening a dialogue with scholars, NGOs, industrial partners and crafts/technology practitioners interested in three-dimensional digital modelling; making; interpretation of; and interaction with, cultural heritage objects and their replicas. We want to assess the state-of-the-art of research in these fields and to establish guidelines for the choice of suitable and affordable solutions, which can then be shared with other museums and cultural institutions. Museum audiences are also involved and will be asked to respond to/interact with the outcomes of the initial phase of activities, in order to inform our methodology and choices for the large-scale project.

The real potential of ever-improving 3D visualisation and ‘making’ technologies is still to be fully explored and as such it is the focus of much attention, as demonstrated for example by a well-attended two-day conference recently held at the British Museum and by the ReACH project, led by the V&A Museum. On 15 March, we ran a half-day workshop in collaboration with the University’s Digital Humanities Network. The workshop brought together experts in a range of topics related to the study of, and interaction with, three-dimensional museum objects, such as 3D sensing, digital modelling, digital and physical making, as well as interpretation and outreach. Speakers and participants discussed the various ways in which digital 3D methods can support and enhance our study and the public’s perception of three-dimensional objects.

Image of panel of speakers. Copyright The Fitzwilliam Museum
Panel speakers. From left to right: Steven Dey, Anais Aguerre, Jonathan Beck and Panel Chair, David Saunders. Image copyright – The Fitzwilliam Museum, Cambridge

Workshop participants were given a demonstration of a structured light scanner which was used to produce models of a selection of polychrome wooden sculptures in the Fitzwilliam Museum collection. They were then asked to work in groups and issue a ‘creative challenge’ to design and produce objects inspired by the original medieval sculptures, based on the 3D models.

Image of Jonathan Beck using a structure light scanner to produce a 3D model of a medieval sculpture. Copyright The Fitzwilliam Museum, Cambridge.
Jonathan Beck using a structured light scanner to produce a 3D model of a medieval sculpture. Image copyright The Fitzwilliam Museum, Cambridge.

The challenge will soon be advertised to members of Cambridge’s Community Workshop MakeSpace and more broadly, and will result in their creations being displayed during a late-night opening of the Fitzwilliam Museum in May. We hope people will feel inspired by the creative challenge and we are very curious to see what they will create!

Image of working together to issue a creative challenge. Copyright The Fitzwilliam Museum, Cambridge
Working together to issue a creative challenge. Image copyright The Fitzwilliam Museum, Cambridge

Find out more about the Polychromy Revealed project

The Fitzwilliam Museum houses the principal collections of art and antiquities of the University of Cambridge, and holds over half a million objects in its care. It leads the University of Cambridge Museums (UCM), a consortium of the eight University Museums and the Cambridge University Botanic Garden, which works in partnership with other Cambridge University collections as well as with museums regionally, nationally and internationally. The University’s collections are a world-class resource for researchers, students and members of the public representing the country’s highest concentration of internationally important collections, all within walking distance of the City Centre. Arts Council England has awarded UCM National Portfolio Organisation status from 2018-2022.

Advanced imaging technologies uncover hidden details on Rubens paintings

Next in our British Science Week 2018 series, Historic Royal Palaces’ Senior Conservation Scientist Dr Constantina Vlachou-Mogire tells us about investigating the Rubens ceiling paintings at Banqueting House…

Historic Royal Palaces is preparing for the 400th anniversary of the Banqueting House, which will take place in 2022. During this major project we have a rare opportunity to access and study in detail the Rubens ceiling paintings, their fabrication technique and current condition.

The Banqueting House is the last surviving building of Whitehall Palace which was destroyed by fire in 1698 (Figure 1). Set within a decorative coffered ceiling designed by the building’s architect, Inigo Jones are nine paintings by Rubens, the artist’s largest and most accomplished works to remain in the context for which they were designed. The paintings were commissioned in about 1629 by Charles I as a testament to the glory of the Stuart monarchy through the depiction of his father James I’s life and achievements.

My beautiful picture
The Main Hall at Banqueting House

These internationally significant paintings are an integral component of the architecture of the hall. Originally the Banqueting House Rubens ceiling paintings were oil-on-canvas stretched on strainers, but since 1907, they were attached to plywood boards. During their long history the paintings have been restored nine times—including in 1940 when they were cut up to evacuate the gigantic panels from the building.

High-resolution multi-spectral imaging

Figure2_MultispectralImages_2018-03-12
Figure 2: Details of the multispectral gigapixel images of The Apotheosis of King James I panel (a. visible light, b. infrared reflected, c. ultraviolet-induced luminescence)

The first phase of our project involved capturing the condition of the paintings in high resolution images (Figure 2). The scale of the paintings, covering a total surface of 243 m2, and their position 17 m from the ground, made this task particularly challenging; however, recent advancements in digital photography helped us to overcome these difficulties.  Collaboration with imaging specialists developed the application of GigaPan technology to document all nine paintings from the ground in visible light and infrared light as panoramic ‘Gigapixel’ images. Ultraviolet-induced luminescence images were taken at close-range from a scaffold, by illuminating small sections of the painting and later stitching the images together to full-painting size. Superimposing the visible, infrared and ultraviolet images allows analysis and detailed classification of the current condition of the paintings as a standing record. This will underpin further investigations and inform the programme of conservation of these important paintings.

We would like to thank the following external collaborators for their expert insights and contributions to the successful progress of this cross disciplinary project: UV/IR imaging Dr Giovanni Verri (Courtauld Institute of Art) and Steven Paine (Paine & Stewart), 3D laser scanning, visible ‘Giga’ imaging John Hallett Jones (Glanville Consultants).

Assessing the light fastness of 16th century Indian paintings (Michela Rampa)

Next in our British Science Week 2018 series, Michela Rampa talks about her student placement at The British Museum, analysing colours in 16th century Indian paintings and assessing light sensitivity. Find out more at The British Museum’s British Science Week event on Saturday 17 March.

Hello, my name is Michela Rampa. I am a student from the University of Rome, La Sapienza, in Italy where I am studying to become a museum scientist. I am currently doing a student placement at The British Museum for my final dissertation. What a fantastic opportunity!

At The British Museum I am based in the Scientific Research Department but also regularly meet with conservators. I am learning how to assess whether museum objects might fade when exposed to light using “microfadeometry”. Microfadeometry is a technique that involves exposing a very small area on an object to an intense light for a short amount of time and recording the colour change on this small area. By comparing the colour change with references, it is possible estimate whether the object is sensitive to light or not.

Michela Rampa BM image1
Examination of a 16th century Indian painting

Why is it so important to assess the lightfastness of museum objects? Many museum objects are light sensitive, for instance: watercolours, prints or textiles. We cannot stop fading from occurring when these objects are displayed, but we can ensure that light-sensitive objects fade so slowly that they will be seen by countless generations of visitors to the Museum in the future. Knowing if an object is likely to fade when exposed to light helps curators to decide how long  it can be displayed and under which conditions. For example, microfading tests carried out on Hokusai’s iconic prints ‘The Great Wave’ and ‘Red Fuji’ last year showed that these should be displayed using dim light for a short amount of time (read about it here).

Michela Rampa BM image 2
Experimental Technical Imaging laboratory in The British Museum

I am currently investigating the lightfastness of some Indian paintings, which will go on display in the new Albukhary Foundation Galleries of the Islamic World at the end of this year. One of them is a very colourful Hamzanama painting made in 1500. (Hamzanama is a series of manuscripts, most of them illustrated, that narrate the legendary deeds of Amir Hamza, the uncle of prophet Muhammad). It is very valuable and I have identified at least 13 different colours on it! I expected that most colours on this painting were produced using mineral pigments and therefore would not fade. However, I am discovering that, on the contrary, several colours, such as green, are light sensitive! I am hoping to perform more analysis to find out why these colours are affected by light. Work in progress!

In the meantime, if you want to know more about the work scientists do at the British Museum, please come and find me and the rest of the Scientific Research team at our annual event ZOOM IN: a closer look at science on Saturday 17 March 2018, 10.00 – 16.00, in the Great Court at The British Museum. Learn about all of the different techniques that are used to analyse the Museum’s collections, handle different kinds of raw materials and see the latest behind-the-scenes technology in action. This is a FREE event too!

Michela can be contacted by email and on LinkedIn. You can find out more about the upcoming Albukhary Foundation Galleries of the Islamic World on The British Museum website.

Five minutes with… Simon Crutchley, Remote Sensing Development Manager at Historic England

Today in our British Science Week 2018 series, we sit down and talk to Simon Crutchley, Remote Sensing Development Manager at Historic England. Remote sensing is the science of obtaining information about an area from a distance, from aircraft or satellites scanning the earth. Read on to find out about his career and the most exciting things he’s been up to…

What’s your scientific/heritage background?

After studying classics at university and spending a few years digging on “the circuit”, as it was called, I got a job with what was then the Royal Commission on the Historical Monuments of England (RCHME) as an Air Photo Interpreter. Since that date I’ve worked in the remote sensing field for nearly 30 years, initially using standard aerial photographs, but over time working with lidar (airborne laser scanning) and more recently satellite imagery.

What’s your role at Historic England?

My primary role at Historic England (HE) is to look at new and cutting edge scientific techniques being used in remote sensing in areas outside heritage, and develop ways to utilise and integrate them into existing workflows. This is both for Historic England and the wider sector.

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

It’s probably a toss-up between two pieces; one is the work I’ve done to try and expand use of the lidar data, released by the Environment Agency (EA) in 2015, by the wider heritage sector, and particularly amateur archaeologists. For this I’ve put together some very basic instructions on the HE website to explain how to access the EA data and then process it so as to produce visualisations to help with recording and interpretation.

Fig_1_Comparative _lidar_visualisations
Comparison between the standard jpg tile provided by the Environment Agency through Flickr (left) and a more advanced visualisation technique, based on the raw data, in this case a Simple Local Relief Model (SLRM) (right). The SLRM is the result of a procedure that separates local small-scale features from larger landscape forms, thereby enhancing features of potential archaeological interest. Tile SU1257 – LIDAR data © Geomatics Group 2008.

The other is the work I’ve done to provide access to the data from the Cannock “Chase Through Time” project, which explored the rich history of Cannock Chase area of Outstanding Natural Beauty. There has been a strong volunteer aspect to the project and one of my key roles has been to create an online map, where it’s possible for users to view the results of the mapping carried out by HE against a surface model derived from the lidar data acquired for the project. Volunteers then have the possibility to download the original lidar data to carry out further analysis themselves and also to take ground photos of features of interest and add them to the map.

Fig_2_Cannock_StoryMap
A screenshot of the StoryMap web app for the “Chase Through Time” project for Cannock Chase, Staffordshire. All across the Chase, previous generations left their mark on the land – including one of the best-preserved First World War landscapes in England.

Who inspires you?

It may sound a bit corny, but people who try to make a difference; people like Bill Gates who devotes part of his admittedly massive fortune to addressing challenges not being tackled by other agencies, such as his malaria initiative.

What do you love most about your job?

The variety. One day I might be providing advice to a member of the public who thinks they may have seen something interesting on Google Earth or wants to know more about lidar; the next I’ll be working with raw lidar data, processing it to bring out subtle features of a landscape no-one has recognised before; the next I’ll be collaborating with other project members working out how to get the data from a project into GIS and shared with others.

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

Heritage Science provides the data that enables us to understand what the world looked like in the past and how our ancestors interacted with it.

Fig_3_Savernake_DSM_DTM
Comparison of the Digital Surface Model (DSM) and Digital Terrain Model (DTM) derived from lidar data for part of Savernake Forest, Wiltshire. The DSM is based on the first return from the lidar pulse and represents the top of the canopy; the DTM is based on filtered data, designed to remove all “above ground” points such as vegetation. This view reveals the presence of an Iron Age enclosure together with several other features. Lidar © Forestry Commission; source: Cambridge University ULM (May 2006).

It’s British Science Week!

It’s that time of the year again! To celebrate British Science Week 2018 (9-18 March), we’ll once more be running a series of blog posts from heritage scientists across NHSF member organisations.

Over the next 10 days, activities and public events around the theme of Science & Technology will be running throughout the country, many of them free – you can find a full list here.

We have an exciting series of posts planned, to make sure that Heritage Science is represented in the festival. What is heritage science? The application of science and technology to cultural heritage, to improve our understanding and enjoyment of it. Keep an eye on this blog to find out about colours and light in Indian paintings, laser scanning the Earth, and plenty more – follow us on Facebook or Twitter to get notified of new posts.

 

Weston cons studio - new book binding
New book binding at Weston conservation studio. © National Trust

 

Heritage science. Fact not fiction.

Welcome to the first post of our new blog! We’ve launched it to coincide with British Science Week (http://www.britishscienceweek.org) to promote the  role of the national heritage science forum and the work of heritage scientists.  We’ll be profiling a different heritage scientist  throughout science week, in a ‘five minutes with…’ series of posts to answer those burning questions – Who are they, heritage scientists? Where do they work? What do they do? What are they like?

To kick us off, five minutes with the NHSF’s co-chairs, Nancy Bell, Head of Collection Care at The National Archives and  May Cassar, Professor of Sustainable Heritage at University College London

What is heritage science?

The term’ heritage science’ is used to encompass all technological and scientific work that can benefit the heritage sector, whether through improved management decisions, enhanced understanding of significance and cultural values or increased public engagement.

Heritage Science tends to be interdisciplinary and some great examples of recent research projects can be found on the website of the AHRC EPSRC funded Science and Heritage programme http://www.heritagescience.ac.uk/Research_Projects.

How did NHSF come into being and what does it do?

The National Heritage Science Forum was set up in 2013 to address the recommendations of the House of Lords Science and Technology Select Committee Inquiry on Science and Heritage and to implement the objectives of the National Heritage Science Strategy. 

The Forum provides a platform to support the policy, research and professional needs of institutions engaged in heritage science. It brings together many disciplines under the wide-ranging, interdisciplinary heritage science umbrella. Through working together, Forum members address the research and practice needs of institutions interested in or engaged with heritage science. http://heritagescienceforum.org.uk/about.php

What kind of organisations participate in NHSF?

The Forum currently has 17 members which represent leading UK organisations active in the field of heritage science. A strength of NHSF is that it brings together the producers and users of heritage science research to maximise the impact of that research, to share resources, knowledge and skills, and to speak as one voice about heritage science. The 17 members include major heritage organisations and academic institutions. A full list is available on the NHSF website, http://heritagescienceforum.org.uk/member-institutions.php where you’ll also find information about joining NHSF http://heritagescienceforum.org.uk/join-us.php.

Can individuals and people who don’t work at heritage organisations get involved?

NHSF is keen to promote understanding of, and involvement in, heritage science. Indeed one of its priorities for 2015 is to identify ways of working with communities, through partnerships with other organisations, to turn its ambition of citizen heritage scientists into a reality.

Whilst only organisations can be members, there are other ways for individuals to get involved with NHSF, for example by following us on Twitter or Facebook.

What’s the most important message you want to convey about heritage science?

Heritage science is critical to our understanding of good curatorial and conservation practice and to improving the understanding and preservation of our shared heritage. Whether policy maker, research institution, user of heritage science research or an individual who cares about the long-term future of heritage we have an opportunity now to work together to create an environment in which creative ideas and innovative techniques can be applied to the past for the benefit of its future.