The restoration treatment started in November 2023, and took more than a year to complete. We know from an invoice from the restorer J.C. Traas, in the Van Gogh Museum archives, that the varnish layer in question was applied in 1933.
Van Gogh himself had made a conscious decision not to apply varnish to his painting, because he preferred a matt surface. However, in 1933 it was common practice to apply a glossy varnish to paintings, regardless of the artist’s intentions.
The aim of this restoration was therefore to remove this undesirable, glossy varnish layer. The varnish – now almost 100 years old – had yellowed with age, and it lay on the painting like a warm, yellow filter.
Due to the thickness of the varnish, the distinct texture of Van Gogh’s brushstrokes was diminished. Removing the varnish would once again reveal the bright, cool colours, the original texture of the brushstrokes and the matt painted surface, with subtle differences in gloss. This would bring the painting back closer in line with what Van Gogh had intended.
It probably only took fifteen minutes to apply the varnish in 1933, but removing it took much longer. Paintings conservator Kathrin Pilz on the restoration: ‘Removing the varnish was a time-consuming process; due to the fragile paint layer, I had to work under a microscope and could only use microtools. Van Gogh applied most of the paint thickly – so-called impasto – so the varnish also needed to be removed from all of the interstices.’
