Since last fall, the sculptures, from the Isenheim altarpiece, considered one of the jewels of the art German, have left the museum Unterlinden from Colmar to join the parisian workshops of the Centre of research and restoration of museums of France (C2MRF). The operation was part of a campaign for the total renovation of the three panels of the masterpiece painted by Matthias Grünewald and sculpted by Nicolas de Haguenau between 1512 and 1516. Already in 2011, a renovation had been contemplated, before being halted due to a controversy sparked by the specialized press, denouncing the lack of rigor in the restoration.

» READ ALSO – That was tending to the large altarpiece of Issenheim?

Since their arrival, the three saints, the figure of Christ, the four reliefs of the apostles and the scroll unfolding adorned with the symbols of the evangelists underwent a battery of tests. These have helped to reveal the high quality of preservation of the original polychromy. In addition to the phases of dusting, cleaning and consolidation of the painting, the scientific committee has given its agreement to remove the repainting dating from the Eighteenth century. The operation will require sixty additional days and additional costs of 24,000. All these works are carried out by a team of seven people, led by Juliette Lévy-Hinstin, manager of restore operations, at the bedside of the sculptures since 1986.

LE FIGARO. – Located in the last panel of the whole, the sculptures have a great symbolic importance in the altarpiece. However, these are less well known than the paintings… How to explain this almost anonymous?

Juliette LÉVY-HINSTIN.- Unlike the sculptures, the paintings are very Renaissance, very striking and astounding realism. When one has seen the paintings, it was the eyes, and the sculptures look more medieval, which speaks much less to visitors. While Saint Anthony is absolutely extraordinary as sculpture. There is a desire to impress. It is very imposing on his throne and he has this look of a judge. The polychromy is in addition completely silver and golden colour so that the paintings do not have gold.

The first phases of cleaning helped restore luster to the sculptures and to reveal the original colors like this blue at the collar of Saint Jerome and the layer of white ermine. Michael Naulin

Why have you chosen to transfer the sculptures in Paris, in contrast to the paintings, restored on site, in Colmar?

We had already carried out a study in 2013-2014 in the chapel. Unlike paintings which are two-dimensional, the sculptures include a lot of hollow, inaccessible to the eye. Move the sculptures allows access to the entire surface of the sculpture and to more easily use the microscopes. These places usually inaccessible are the most interesting to discover the original polychromy.

What are the different steps of this operation of restoration of the whole sculpted?

The steps of dust removal and consolidation of the polychromy have been carried out on-site, in the city of Colmar. In Paris, we started the tests of the clean-up. I also took over the study at the microscope of the stratigraphy of the polychromy, in other words, the analysis of the different layers of paint. This has allowed me to differentiate between the original colours and the repainting of the end of the Eighteenth century, thanks to ultraviolet light. X-rays of the sculptures have allowed us to see the joints of the wood and the metal parts used to hold it all together.

The x-rays, as here, that of St. Jerome, allow us to distinguish the assemblies of the wood and any metal parts used to hold it all together. Michael Naulin

That have enabled us to discover these different tests made in the workshops of the Centre of research and restoration of museums of France?

They were able to confirm the quality of preservation of the original colors. This famous glaze blue (above the level of the collar of Saint Jerome) is very rare in the Sixteenth century. In the baroque period, there is a lot of glaze over silver leaf, which made me think that the color was in the Eighteenth. I was able to confirm that this glaze was original. It is quite unexpected to have a polychromy also well preserved. Everything is original apart from some repainting, including the bases of the sculptures.

The decision was taken to remove the repainting of the Eighteenth century to reveal the original color. Don’t delete a part history of the sculptures of the altarpiece?

This is a heavy decision, taken very rarely. But it is also very rare to have a colour entirely of the time. Colors
are often removed, or repainted. Here, it’s fabulous luck.
At the committee’s November, there has been a strong reluctance. I wasn’t sure at this point you have identified all of the repainting.
We could end up with a polychrome half of the Eighteenth and half of Sixteenth century. Thanks to the confirmation tests, the sculptures will recover their level of the polychromy of the early Sixteenth century. The operation is worth to restore harmony between the sculptures and the paintings. The green malachite and blue azurite are very bright and are two colors that can be found with the table. The sculptures are going to be so much more spectacular and will recover their sacred dimension.

The sculpture of Saint Antony, enthroned in the workshops-laboratories (C2MRF), located in a wing of the Louvre. ALAIN JOCARD/AFP

What techniques are used to remove the repainting?

The greater part of the work is performed with a scalpel under a microscope. It takes four days to Saint Jerome and Saint Augustine, sixteen to St. Anthony because there is a lot more surface area and the overpaint is more difficult to remove on the green original. But in general, the painting of the Sixteenth is very adherent.

Since 2011, many precautions are taken in the progress of the restorations. Is there a coordination of the work with the team in charge of paint?

We are under the eyes of the scientific Committee. With the person in charge of the paintings, we decided to compare all of the layers. We begin, moreover, to ask us if Matthias Grünewald (author of the paintings of the altarpiece, editor’s NOTE) would not have worked on the sculptures. The painted panels are in wood of linden, as well as sculptures and the care of execution is also comparable. We expect the analysis of the wood as a whole could have been made in the same workshops. Study of a sculpture so very thorough always brings discoveries. There is still a lot of things to discover and it is very motivating.

overview panel of the Isenheim altarpiece where are the sculptures of Saint Augustine (left), St. Anthony (centre) and Saint-Jérôme (to the right). AUC anne samson communications (ASC)

» Discover the program of guided tours of the Figaro Escape here.
» Follow all the info in the Figaro culture on Facebook and Twitter.