Stained Glass - Art at the Glass Surface
Cambridge - Monday 4th and
Tuesday 5th September 2017



Barbara Trichereau
<barbara.trichereau@culture.gouv.fr>

article posted 18 May 2017

Barbara Trichereau, engineer at the department of stained glass windows conservation, Research Laboratory for Historical monuments (LRMH) in France. She graduated in Physics at the University of Bordeaux (France) and completed a master's degree in physics applied to archaeometry. She carried out her thesis in the characterization of obsidian from Melanesia with Portable X-Ray Fluorescence spectrometry with the faculty of Art at the University of Auckland, New-Zealand. She is an associate member of the International Scientific Committee for the Conservation of Stained Glass (Corpus Vitrearum-ICOMOS).


Restoration of Louis-Germain Vincent-Larcher in the 19th century at Troyes cathedral
Barbara Trichereau1, 2*, Claudine Loisel1, 2

This year an exhibition will be held from the 3 June to the 31 December 2017 in the Cité du vitrail in Troyes on the work of Louis-Germain Vincent-Larcher (1816-1894), craftsman and glass painter [1]. Original panels from the cathedral of Troyes and restored ones will be presented to expose the restoration processes he set up back in the 19th century [2]. This project has been the occasion to gather together scientists from the LRMH, art historians and glaziers to continue the investigations on his particular working processes and increase the knowledge of his restoration techniques [3].

Louis-GermainVincent-Larcher realized many restoration works among which the cathedral Saint Pierre et Saint Paul in Troyes took an important place. He assumed that a good and acceptable restoration work is one in which the original pieces and those from the 19th century cannot be distinguished. To this purpose he used different surface treatments for the glasses in order to match modern, reused and old glasses. To lower the transparency of newly made glasses, he employed two different kinds of painting, patina and couverte, made from his own recipes, just like he used to manufacture his own grisaille and enamel. Patina could be defined as a cold paint layer applied on the interior of the glasses while couverte is a paint layer applied on the exterior, and annealed.

A collection of raw materials found on his studio has been preserved and given to the local archive department by his successors. For this project, we have been able to observe and analyze these materials with 3D-microscopy, Scanning Electron Microscopy coupled with Energy Dispersive X-ray spectroscopy (SEM/EDX), Fourier transform infrared spectroscopy FTIR and X ray diffraction XRD in order to make a full characterization of the pigments we should find on his actual restoration work. In the meantime two panels created by Louis-Germain Vincent-Larcher and presenting such surface treatments were observed and we have been able to carry on analyses on them as well to compare the raw materials with the restoration works. Grisaille powders and pigments have been identified within the raw materials and also on the glasses helping us to understand the restoration processes used by Louis-Germain Vincent-Larcher.

Reference:

[1] Elizabeth Pastan, Reassessing Vincent-Larcher's restorations of the ambulatory chapel glazing at Troyes cathedral - Corpus vitrearum News letter, n° 48, mai 2001. - Bulletin de liaison hors-série 2001 / section française de l'Icomos, p. 32-36.
[2] Sylvie Balcon, Vincent-Larcher et la restauration des verrières hautes du chœur de la cathédrale de Troyes - Corpus vitrearum News letter, n° 48, mai 2001. - Bulletin de liaison hors-série 2001 / section française de l'Icomos, p. 27-31.
[3] Ernest Bertrand et al, Vincent-Larcher et Martin-Hermanowska, Rapport sur les vitraux peints, Extrait de : Mémoires de la société d'agriculture, des sciences, arts et belles-lettres du département de l'Aube, n° 93, 1er trimestre 1845, p. 1-39.

Institutions:

1 Laboratoire de Recherche des Monuments Historiques, Ministère de la Culture et de la Communication, 29 rue de Paris, 77 420 Champs-sur-Marne, France
2 Sorbonne Universités, Centre de Recherche sur la Conservation (CRC, USR 3224), Muséum national d'Histoire naturelle, Ministère de la Culture et de la Communication, CNRS ; CP21, 36 rue Geoffroy-Saint-Hilaire, 75005 Paris, France