CHANGE Virtual Training School

Photo: Japanese Woodblock Print: Under the Wave Off Kanagawa, The Metropolitan Museum of Art.

CHANGE Virtual Training School

As for many others, the virtual seminars have become a big part of the working day of our project members. When the pandemic stopped us from meeting in Paris for the CHANGE School France this spring, we decided to go on with parts of the training programme that could actually fit well, or at least OK, in a virtual context. The CHANGE Virtual Training School emerged this autumn, and all the 15 Early Stage Researchers are joining short virtual sessions covering different topics once a week from November to January.

Japanese Woodblock Prints

One of the perks of offering the training virtually is that it is easier to invite people from all over the world to hold a presentation. A virtual event made it easier for Marc Vermeulen, a research associate at Northwestern University in the US, to join the event and give us a presentation about his colour analysis of Japanese woodblock prints. It was interesting to learn how he could infer the chronology of the print production.

As the Japanese woodblock prints were most likely produced in an industrial way, like a manual assembly line, the workers were probably using similar paper as well as similar pigments and colour mixtures in each batch. Based on measurements of the pigments and colourants, and especially the mixture used in the outlines, he could group the pictures into clusters using statistical methods. Then, by comparing the line quality of the similar prints found in different clusters, he could conclude in what order the clusters were printed – creating a chronology of the production.

Infrared imaging

Photo: Painting of a sleeve, where the left is showing the underlines (C2RMF).

In a painting, you may find information that is not visible to the human eye. Clotilde Boust, head of the Imaging group at the Research Department of C2RMF, explained how infrared imaging can be used to go through the layers of the painting and detect the carbon and the pigments of the painting. If it is made carbon drawing or writing in the support of the painting, the infrared will detect them, revealing the text normally hidden under the paint. In this way, we can see if the painter has made any changes as he or she went along with the painting and we can easier understand the techniques the painter made us of.

Photo: The same painting with different lighting when photographed (Van Gogh: Mademoselle Gachet, Musee d’Orsay)

By using different light and imaging techniques, you can detect and document information about a painting that is not visible on a picture taken with a regular camera. For a relief painting with a lot of structure in the surface, a regular photo of this will in many cases show a flat structure. Using a raking light, this surface will get more visible also in the picture, making it possible to compare the photos from different time periods to detect changes that occur in the surface over time.

3D scans

When working with Cultural Heritage (CH) Objects, you are often working with very fragile items. The risk of damage the objects are limiting what sorts of analysis you can conduct. Charlotte Hochart and Alexis Komenda from C2RMF gave us an insight to the use of 3D scans for analysis of CH objects, allowing assessment of the object in all angels without touching the fragile object. They also showed the interesting work on documentation of the fire damages in the Notre Dame cathedral in Paris where they used drones to scan inside the cathedral. Also, cable cameras were running on a line to take pictures where the drone couldn’t fly due to damages causued by the fire.