A final varnish layer on a finished painting has been an artistic practice for centuries. Artists often apply a transparent varnish to give saturation and their desired level of gloss to the painting, as well as to provide a protective coating. Until the 20th century, natural resins such as dammar and mastic were usually used. Over time these varnishes can become discoloured as the resin degrades, eventually causing a yellow to brown colour shift to the artwork. Whites look a dirty yellow, while blue skies are transformed to a stormy green.
After research and discussion with curators, a conservator may choose to remove a discoloured varnish if the removal can be done safely without risk to the underlying paint layers. This was the case with our recent acquisition Heron’s home by Queensland colonial artist and taxidermist Anthony Alder. Dating from 1895, the painting depicts two meticulously rendered Nankeen night herons in a riverine landscape, but the deteriorated varnish was giving it a strong yellow cast overall.
Watch as I remove the varnish layer using cotton swabs and a carefully-tailored solvent blend, revealing the artist’s original colours, and restoring the full tonal range and sharpness of image.
Currently on display in the ‘Art in colonial Australia’ room, Josephine Ulrick and Win Schubert Galleries, Queensland Art Gallery (QAG)