Go behind-the-scenes as we conserve ‘Red-tailed Black Cockatoos’

Tue 17 Oct 2023

Large scale paintings from Queensland’s Colonial period are extremely rare. Currently on display in the Australian Art Collection (Gallery 10, Josephine Ulrick and Win Schubert Galleries) at the Queensland Art Gallery is an oil painting that has recently been conserved while research into a replica frame have brought it back to its former glory. This is the first of a two part focus on Red-tailed Black Cockatoos, a partner to another work by the artist in the QAGOMA Collection Heron’s home.

Red-tailed Black Cockatoos by Anthony Alder (1838-1915) dated c.1895 (illustrated) shows a male and female pair of Red-tailed Black Cockatoos (Calyptorhynchus banksii), also known as Banksian or Banks’ Black Cockatoo, native to Australia and found in eucalyptus woodlands or along water courses. This species has disappeared from much of its former range in northern New South Wales and southeast Queensland.

Alder was the eighth of ten children, his father, Anthony Alder Snr, was a taxidermist and his mother Elizabeth Arundell was a naturalist. Alder trained in the family’s taxidermy and casting business ‘Alder and Company’ in Islington, London before he arrived in Brisbane in early 1862, and probably worked for the taxidermy business ‘Arundell and Alder’ before travelling to Somerset, Cape York Peninsula, Far North Queensland in 1864, where he spent some time collecting specimens.

Alder was the most prominent taxidermist in colonial Queensland and from 1907, was widely admired for his dioramas which he painted for the Queensland Museum when it occupied the Exhibition Building (illustrated). While taxidermist to the Museum he created (and painted) several dioramas which remained on display until the old Museum building closed in November 1985, before moving to the Cultural Centre.

He also contributed a series of illustrations of birds to the Queenslander (illustrated) and was regarded as most important Australian painter of birds after Silvester Diggles (1817-80).

Anthony Alder (Standing 3rd from the right)

The (Old) Queensland Museum (Exhibition Building)

Illustrations of birds in the ‘Queenslander’ by Anthony Alder

Red-tailed Black Cockatoos

Red-tailed Black Cockatoos entered the QAGOMA collection in 2014 after spending some time stored in a shed in the Warwick region of Queensland (160km west of Brisbane). Likely from its time, the painting was subject to extremes of climate and accessible to animals as the paint surface had extensive dirt and bird droppings, the paint was generally cracked while some paint was lost. The painting had been varnished, however the varnish had become very yellowed, uneven and brittle and desiccated from age. Luckily, there was no damage to the canvas nor the painting’s stretcher, and on arrival at the Gallery, the work was received framed in its slip only — the outer decorative part of the frame was missing.

Before conservation: ‘Red-tailed Black Cockatoos’ 1895

The painting showed excessive drips, as you can clearly see, and the white strip in the center of the painting is primer where the paint has been lost due to corrosion. Bird droppings are very acidic (pH 3.5 to 4.5), the (mostly) uric acid initially begins to burn and etch the paint’s surface, the longer it remains, the greater the damage. Dirt and discolouration can also be seen in the sky.

The reverse of ‘Red-tailed Black Cockatoos’

The reverse of Red-tailed Black Cockatoos (illustrated) shows us the artist used unprimed cotton canvas tacked to a key-able stretcher, dirt and insect droppings can also be seen. A major part of the restoration involved initial cleaning of the painting before the varnish and other dirt layers could be removed. Cleaning was carried out under the microscope (illustrated) and different cleaning systems were used for different types of droppings.

Cleaning was carried out under the microscope

Detail of insect droppings

Detail of insect droppings. Note how the insect droppings have affected the paint – etching it away.

Droppings being removed

As the painting had been varnished, some droppings could be mechanically removed by carefully breaking them and pushing them off the varnish using a very tiny scalpel.

Use of conservation gels

Other droppings were very hard and required the use of conservation gels and other techniques to make them soft enough to remove.

Damage to the paint

Damage to the paint can be seen in the black of the cockatoo’s feathers, the paint has been etched away.

White uric acid

Near the artist signature, droppings on the paint surface show the white uric acid as a perimeter of white around the dark dropping. Fortunately these could be removed without any damage to the underlying paint.

Paint eaten away

In long streaks, droppings had also caused damage, where the paint was eaten away revealing the white ground of the painting, as can be seen in the details of the feathers.

Residual droppings

Under the microscope, in close up of around 20x magnification, you can see residual droppings (brown) on the left, and then an area where the droppings have fallen off and taken paint with them (right). Residual droppings had to be very slowly and carefully removed so as to not dislodge any more paint during the cleaning process.

Age cracking

Age cracking can also be seen, together with tiny paint losses. This type of paint cracking can be exacerbated by exposing an oil painting to fluctuations in temperature and relative humidity as the canvas support is flexible and can swell and contract as the humidity changes, but as the paint is less flexible, it cracks.

Cracking

Cracking is most obvious in areas of high canvas tension such as the corners, as seen here in the top right corner before treatment.

Varnish removal

Once all the dirt and droppings were taken off, the discoloured varnish layer could be removed using solvents, the varnish removal has begun in the top right corner, revealing a bluer sky under the yellow varnish.

Conservation grade varnish applied

Once all the dirt and varnish was removed, a new conservation grade varnish was applied to the surface by brush to saturate out all the colours. This is done with the painting lying flat.

Re-integration of the paint losses

Once the varnish has set, re-integration of the paint losses is undertaken using a tiny sable brush and conservation grade resin and dry pigments. Pigments are mixed to match the colour and gloss of the original paint. This in-painting is fully reversible as it is soluble in solvents that do not affect the paint layers.

Once the in-painting is completed, another layer of varnish is sprayed on so that the black cockatoos become gloriously glossy and saturated again. The age cracks in the paint within the sky are not reversible, but the paint is now stable and the painting is ready for its new frame and for display.

The moral of the story is that it’s not such a good idea to leave your oil paintings in a shed where temperatures can be extreme, and if you do need to store them, its best to wrap them safely to avoid any damage.

After conservation: ‘Red-tailed Black Cockatoos’ 1895

Anne Carter is Conservator, Paintings, QAGOMA

Featured image: Once the varnish has set, re-integration of the paint losses is undertaken using a tiny sable brush and conservation grade resin and dry pigments. Pigments are mixed to match the colour and gloss of the original paint. This in-painting is fully reversible as it is soluble in solvents that do not affect the paint layers.