Questions remained unanswered – particularly the authenticity and purpose of an under-drawing which was discovered during the conservation of the sculpture in phase one of the project, and whether the palette and techniques found in the original polychrome layer were comparable to other pieces in the Gualino group. Testing our data against others in the Gualino group was the next step in order to be able to gain a more meaningful insight into workshop practices in 14th-century Italy.
Making our findings accessible to the public had always been a key goal and the second phase of the project would also allow us to achieve this.
Diana de Bellaigue, Artefact Conservator
Lore Troalen, Scientist
Xavier Dectot, Keeper of Art & Design
Jerome Castel, student intern in Collections Science Section
Jessica Chloros, Isabella Stuart Gardiner Museum, Boston USA
Mark Richter, University of Glasgow
Jennifer Anstey, MA student, University of Glasgow
Sam Ramsay, Glasgow School of Simulation and Visualisation
Jared Benjamin, Glasgow School of Simulation and Visualisation
Tom Challands, University of Edinburgh
Ailsa Murray and Damiana Magris, Historic Environment Scotland
Infrared imaging confirmed the presence of under-drawing directly on the wood in three areas where wood is exposed:
The Virgin’s eyes
The Christ Child’s eyes
The Virgin’s tunic.
A sample analysed using a Scanning Electron Microscope (SEM) confirms this to be carbon-based.
Binding media analysis was not possible due to constraints of analytical equipment at our disposal.
Working with conservators at the ISGM, St Agnes was analysed using the following techniques:
Paint samples were brought back to the UK for analysis included in a student project by Jerome Castel, supervised by Lore Troalen.
The samples are due to be sent back to Boston for UV imaging in the Conservation Department.
A joint paper on the results comparing methods and techniques on our two sculptures is planned for 2019/2020
We collaborated with Dr Mark Richter lecturer in technical art history at the University of Glasgow. Working with a Technical Art History student on her Master’s dissertation, we prepared sample boards using the materials revealed through scientific analysis in phase one of the project. She researched the techniques and recipes required to make the paints and made these up in the lab. We then painted out sample boards using these materials and techniques.
Traces of original decorative detail are evident on the surface of the sculpture in places and the cross-section data supported this with combinations of metal foils and glazes. However, despite the clues for several areas, we had no concrete evidence of how this decoration may have looked. With the help of Helen Wyld, Senior Curator of Historic Textiles at National Museums Scotland, we looked for cross-references in contemporaneous panel painting. Choosing simplified designs to avoid too much fanciful make believe, we selected various patterns for the neckline of the Virgin’s tunic and the Christ child’s cloak. We were lucky in that the pattern on the Child's cloak could be seen clearly with Infrared Reflectography, so this pattern could be copied.
In phase one of the project, Glasgow School of Simulation and Visualisation or SimVis had made a 3D structured light scan of the Madonna and Child. We now commissioned the use of this to make a 3D colour-rendered model. We wanted to be able to show the construction of the wood, the under-drawing, the preparation layers and the polychrome surface.
To achieve this, SimVis combined their model with a model of the wooden core created using the CT scan data by Tom Challands of Edinburgh University. The result is an animation showing the sculpture in the round, starting with the carved wooden elements assembled with nails (from the CT data), then the marking in of the underdrawing, the coating of white calcium sulphate preparation layer or ‘gesso’, followed lastly by the polychrome surface including impressions of the brocaded surface. Areas for which there was not enough polychromy data were left wood-coloured in the model. Equally, for the skin tones, where recreating the subtleties of a textured tonal painted surface would be particularly difficult, we decided to leave wood-coloured.
This film shows how the sculpture was created and may originally have looked.
KT Wiedemann Foundation