After being on display in the museum for decades, the time has come to restore the famous panorama "The Columns of Athens" (1806-1822) by Joseph Dufour, one of the most illustrious wallpaper manufacturers of the 19th century.

Issues

The ten panels of the panorama wallpaper was extensively restored in the early 1990s.

In recent years, the four panels on display in the museum have begun to show signs of structural damage, mainly due to the natural ageing of the materials in the wallpaper.

There are surface tension issues, which have led to deformations and tears that could worsen over time.

Restoration

The entire panorama will be restored over the course of roughly two years.

This time will be needed to re-establish the physical and structural integrity of the work, while respecting its material history.

Transport

Work began on 10 November 2023. Two of the ten panels have already been sent to the museum's restoration workshops.

Technical and photographic analysis

We do a visual analysis of artworks before restoring them. This informs the next steps.

With the help of a technical analysis, we can better understand the work’s physical properties, identify its components and establish their condition. This is essential for planning and carrying out conservation measures.

For works on paper, photographic analysis is a valuable tool because it is a non-destructive method, using a wide range of techniques and light sources.

UV photography

UV photography gives us information about the carrier material, the pigments, the solvents and the binders of the paint. It helps us identify areas that have been retouched with or without varnish, in addition to biological changes such as mould stains and mildew.

Infrared photography

This technique reveals information invisible to the human eye, i.e. sections that have been painted over or preparatory drawings. It can also help decipher inscriptions that have become illegible over time.

Microscopic analysis

Binocular microscopy renders the different layers of paint visible, which means we are able to take samples from each layer.

Stratigraphic analysis

Another step in our research before restoration involved gathering information about the composition of the pigments used in wallpaper production and the manufacturing technique. To this end, we conducted a stratigraphic analysis using small sample extractions.

Objective

Identifying the pigments can help us determine the best treatment method to follow, especially since some colours used in the past may pose a health hazard to the operator. This is the case, for example, with Scheele’s Green, a highly toxic colour introduced in the late 18th to early 19th century, which was used in everything from wallpaper production to cosmetics, toys, clothing, and more.

Precautions

Since Scheele’s Green can release toxic fumes when it comes into contact with moisture (which could occur during wet restoration), a series of tests aimed at identifying it and health and safety protocols were established to mitigate any potential health risks: personal protective equipment (protective gloves, FFP2 mask, goggles, Tyvek suit), extractor hoods, and proper ventilation in the workspace.

Sample collection

Since stratigraphic analysis requires samples, to avoid damaging the artwork, it is important that the samples:

  • Are very small (sample the size of a pinhead)
  • Are taken from concealed areas, ideally where there are cracks or fractures in the paint layer

Our main goal being to identify the possible presence of Scheele’s Green, the samples for the stratigraphic analysis were primarily taken from blue and green areas: the sky (which had been heavily retouched during previous restorations), the foliage, and the clothing.

Preparation of stratigraphic sections

The samples were taken using a scalpel and embedded between two plexiglass cubes with the help of an epoxy resin. To analyse the colour, appearance, and the sequence of layers in the sample cross-section, the plexiglass was polished to obtain a smooth surface. The prepared sections were then examined under an optical microscope. Initially, the samples taken were too small and fragmentary, making it difficult to identify the layers. To obtain a clearer reading, we had to cut a small piece of wallpaper from the edge of a tear.

The result

  • Pale blue layer, uniformly coloured, with a few cold blue speckles
  • Very thin layer in greenish-blue, uniformly coloured
  • Thick transparent layer (restoration varnish or wallpaper paste)
  • White layer with fine round blue specks (first overpainting)
  • Thin dark transparent layer (restoration varnish or paste after the first overpainting)
  • Pale turquoise blue layer, uniformly coloured with some lighter areas (original primer)
  • Very thin transparent layer (isolation or wallpaper paste)
  • Ochre, fibrous layer (paper support material)
  • Thick yellowish transparent layer (paste)
  • Pale turquoise blue layer, uniformly coloured (original blue from the overlapping wallpaper sections)

So far, no green pigment has been detected.

To confirm this result, further non-destructive tests will be carried out, and we will provide more details in the next update, so… stay tuned!