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SGS is the only art service provider in its category to maintain a global presence.

With an international network of accredited art conservators, proprietary software, rigorous museum-level procedures and a dedicated laboratory in the Geneva Freeport, SGS has developed a unique system to monitor the condition of artworks globally. Our experts help clients to analyze and date works of art and gain in-depth knowledge of their materials, techniques and condition. SGS also helps art experts to authenticate artworks, uncover unknown masterpieces, and provide inventories of art collections, as well as document and verify the condition of artworks before and after logistical operations.

Recent advances in technology applied in the art world (including infrared reflectography, UV fluorescence photography and X-ray) mean that previously hidden layers can be revealed and can present essential clues about the history of art works as well as the materials and techniques used by an artist. These imaging techniques enable our experts to provide objective scientific elements that are often crucial to dating or authenticating an artwork or to determining its state of conservation.

SGS Art Services was used by private collector Mme Manuela de Kerchove d'Ousselghem to search for unaccounted artworks by the Belgian artist René Guiette (1893-1976). The Belgian painter, illustrator and art critic was made a member of the Compagnie de l’Art Brut in 1948. Today, his work can be seen at galleries and museums, including Paris’s Musée Royal des Beaux-Arts d’Anvers and Brazil’s Museu de Arte Moderna de São Paolo.

As the granddaughter of the painter, Mme de Kerchove has dedicated more than 40 years to researching and cataloguing the painter’s work. Her research culminated in 1991 with the publication of the first “catalogue raisonné”, which included around 3,000 of Guiette’s works. Since then, Mme de Kerchove has continued to research archives and scour the world in her quest to build a comprehensive database of his life’s work and enrich understanding of the artist’s career, influences and legacy.

A Painting Beneath a Painting

Guiette’s painting “Paysage” (1953) was examined by SGS Art Services to evaluate the existence of an underlying composition, as paint losses along the edges revealed bright blue and yellow paint, which were inconsistent with the brown, red and black colors on the surface painting.

'Paysage' by René Guiette, 1953

Above: On the left: ‘Paysage’ by René Guiette, 1953; on the right, top and bottom are highlighted details of the paint losses that revealed bright colors contrasting with the existing composition.

To determine the existence of any potential underlying compositions or preparatory drawings, SGS Art Services used infrared reflectography and digital X-ray imaging. These techniques revealed an entirely new painting, dating back to around 1941, that was identical to one Mme de Kerchove had been looking for.

Using X-ray microfluorescence (XRF), SGS was able to detect the different materials used by Guiette in each composition. In “Paysage”, carbon black, cadmium red, red ochre and umber were the main pigments used, whereas the earlier composition featured zinc white, (presumably) Prussian blue, cobalt-based blue, chrome-based yellow, cadmium red and umber – pigments that were responsible for the bright, contrasting colors that were evident in the missing layers of the surface painting.

Art works

Above: On the left: visible light photograph of “Paysage” by René Guiette, 1953; on the right: x-ray image of the same painting.

In the course of her research, Mme de Kerchove had discovered a photograph of the artist with a partial view of the underlying painting. Comparison with the X-ray image enabled a reconstruction to be made of the missing section from the photograph. Having established that both compositions were by René Guiette, SGS determined that the artist himself had applied a new base layer over his initial painting to prepare it for the composition made in 1953.

Art works

Above. Left: a photograph of the artist René Guiette, with a partial view of the painting. Right: a digital X-ray image, in landscape orientation, with highlighted features from the underlying painting in red, for the features also visible above left; and in green, for new features discovered.

Even if the technology existed to enable the two paintings to be separated, would Guiette have wanted both paintings to remain? For whatever reason, the artist chose to conceal the previous painting. Respecting this, the painting’s owner, Mme de Kerchove, has decided not to restore the painting but to leave the underlying paint layer visible. She will continue to look for more works from her grandfather’s Cubist period. However, she now knows that if she does not find them, there is more than a possibility that they will have been painted over.