The painting The Temple of Concordia at Agrigento was completed in 1857. Leo von Klenze based the composition on preliminary studies and open-air sketches made in Sicily. He subsequently executed the painting in his Munich studio.
The work measures 88.7 by 131.5 centimeters. The textile support is stretched over a wooden stretcher, which may be original. The support has a double ground: a common technique in Klenze’s era. A layer of white was applied in a half-covering manner over the lower ground of dark ochre. Both grounds are clearly recognizable in the cross-section (see below). For the underdrawing the artist used a dark material: probably either a pencil or black chalk. Infra-red technology (see below) reveals staffage figures and vegetation, drawn in a free and masterly manner, as well as rigorous construction lines which attest to Klenze’s architectural precision. Surprisingly, aids for transposing the composition, such as grid lines, are not present.
Above the underdrawing is a thin underpainting and then the paint layer itself. The blue pigment Klenze used could be Prussian or even synthetic ultramarine blue, a pigment developed in the 1830s. Remnants of the original varnish were found only in grooves in the paint surface.
During the Second World War the painting was damaged in the lower right-hand corner; it was subsequently restored in the 1950s and again in the 1970s. During this time the painting was relined: canvas was affixed to the backside of the support for reinforcement. Flour paste was used as an adhesive: an aqueous glue which is generally applied (indeed soaked into) the entire fabric surface and then adhered to the existing support by applying great pressure. The craquelure, with broken and sharp edges, presumably resulted from this process, which exposed the painting to a high degree of moisture. The damages to the paint layer were filled and retouched. In the shadowy lower section of the painting the retouched parts have hardly aged; the colours blend in adequately and dried only partially matte. However, the losses in the sky that were retouched (left of the temple) are now heavily discoloured. A coat of natural resin varnish completed the initial restoration. It was applied ir-regularly with a brush and dried partially matte. The degree of yellowing suggests a natural resin varnish 50 to 60 years old . But air pollution caused the most dramatic damage to the paint surface. For decades, the painting hung in the workroom of a heavy smoker. The deposits on the paint surface consisted therefore primarily of nicotine, which resulted in enormous discolouration: from sky to sea the Mediterranean landscape was fully coated in a yellow glow.
The painting required above all conservational measures. Removing the layer of nicotine from the paint surface – and thus the yellow discol-ouration – was the primary objective. In addition, the painting required a historically accurate frame.
The paint layer was tested for stability and partially stabilized. After a comprehensive series of tests, the surface was cleaned using an aqueous solution of sequestrants and demineralized water, followed by a solution of demineralized water only (see above). The matte areas were treated with a natural resin varnish solvent. The design for the new frame is based on a historical Schinkel frame from the museum’s collection.
Partners/Funding: The restoration and reframing were fully financed by SMB funds. The painting was donated by Dr Oliver Lepsius.
Duration of the restoration: January to March 2018
Duration of the exhibition: Concordia – Art and Science in Harmony: 28 March to 15 July 2018
Contact person: Kristina Mösl, Leitung Kunsttechnologie/Restaurierung Alte Nationalgalerie, Staatliche Museen zu Berlin