Conservation project: Danaë and the shower of gold

Conservation project: Danaë and the shower of gold Introduction The Geelong Gallery works closely with the Victorian Centre for the Conservation of Cultural Material (VCCCM) on the conservation of the art works in its collection. In 1992 a major conservation treatment was carried out on Geelong's 'Titian'. History and provenance This painting is a copy of Titian's Danaë and the shower of gold. The original painting by Titian (died 1576) was commissioned by the Farnese family in Rome in around 1546. The copy is almost exact, except that it is slightly larger than the original, and slightly elongated. This suggests the copy was made from the original rather than from an engraving. The copy was said to have been shipped from Britain to Geelong during the 1840s by Dr. James Kilgour. During the 1850s it was stored at Charles Ibbotson's wool store Dalgety, Ibbotson & Co., and remained there forgotten when Kilgour fled the colony under a cloud of scandal. The painting was discovered in 1882 by the store's recently-appointed manager, David Aitken. When it remained unclaimed it was sold to the art dealer C.E. Charity (1845-1924) for £5. Charity believed the painting was by one of Titian's pupils; he had apparently discovered a piece of parchment attached to the picture which bore the initials of the artist together with a second set of initials. He intended to forward the painting and parchment to London but, it was rumoured, after cleaning the parchment and leaving it to dry it was destroyed by rats. The work was loaned to the Gallery from 1918 until 1933 when the trustees of Charity's estate sold it to the Gallery. The Conservation and Technical Examination The Geelong picture went to the laboratory of the Victorian Centre for the Conservation of Cultural Material (VCCCM) in 1992 for treatment and technical examination. The analytical work undertaken by the VCCCM helped to establish a date for the painting, as its origins prior to coming to Australia in the 1840s are unknown.

[Fig.1: Titian, Danae and the shower of gold. The original painting is in the Museo di Capadimonte, Naples] The conservation treatment involved three major stages:
a.	removal of layers of discoloured varnish which were obscuring the image
b.	removal of an old lining canvas and re-lining with a new canvas in order to support the fragile original
c.	retouching of the losses and revarnishing

[Fig.2: During varnish removal. The painting appeared murky and almost monochromatic prior to the varnish removal. The colour range seemed typical of a nineteenth-century copyist's palette. However, as the old discoloured varnish was removed, a cooler cleaner tonality emerged.]

[Fig.3: Prior to removal of the old lining canvas. A previous restorer had lined the painting. This old lining canvas was adhered with an animal skin glue and starch composition. It bears an interesting painted emblem, which could identify a previous owner.]

[Fig.4: The back of the original canvas before re-lining. After preparation of the original canvas, conservators at the VCCCM attached a new lining canvas with a wax and resin adhesive.] 2. Visual examination. Removal of the old discoloured varnish revealed that some colour changes had occurred as the painting had aged. The sky was once a more intense blue, and the curtain was a rich purple rather than the pinkish grey it now is. These colours were therefore more faithful to the original than they now appear.

[Fig.5: The curtain at the left. Look at the painting and see where the mauve colour has faded where it has been most exposed to light.]

[Fig.6: The sky at the right edge of the picture. The pigment is less faded where it has been protected by the frame.] 3. Technical and scientific examination Several methods of scientific and technical examination gave more information about the structure and materials of the painting.
a.	X-ray photographs can sometimes reveal underdrawing or changes made by the artist.

[Fig.7: X-radiograph showing the underdrawing of Danae's foot. The artist has sketched the out-line of Danae's foot without correction or alteration. Since s/he was making a copy from another composition, there was little need for compositional experiments.]
b.	Microscopy of paint sample cross-sections. In order to understand how the artist built up the layers of the painting, small samples of paint were mounted in a polyester resin block, and the block then ground away to reveal the paint sample in cross-section. Under high magnification, it is possible to see details of the paint and varnish layers.

	The preparator layers in the sample in Fig.8 are particularly interesting. Commercial firms of artist's colourmen were routinely (though not exclusively) supplying prepared canvases to artists by early in the nineteenth century. However, since there is no commercially applied white priming layer here, this painter must have prepared his/her own canvas. The use of a darker layer followed by a lighter layer, which we also see here, was particularly used throughout Europe in the eighteenth century.

[Fig.8: Paint sample, taken from near the cherub's head. This was photographed in visible light at 100 times magnification. The bottom layer is a glue sizing layer. The next two layers of reddish colour are the ground or preparatory layers, applied by the artist to give a suitable texture and colour for painting on. The blue layer is the coloured layer which we see when looking at the painting, and on top of this is a discoloured varnish layer.]
c.	Information from electron diffractive x-ray analysis (EDXA) can identify elements present at the surface of a sample. By focussing the elctron beam on a particular pigment grain, we can sometimes gain information to indicate what the pigment is among several likely ones. We used EDXA to identify the blue pigment of the sky because mnay new blue artists' pigments were introduced during the eighteenth and nineteenth centuries: identifying a blue pigment can therefore indicate quite a specific date for an undated painting of this period. Possible blue pigments in the blue paint layer included natural ultramarine, smalt, cobalt blue, and synthetic ultramarine (also called French ultramarine). Cobalt blue was introduced in 1810 and it largely replaced the costly natural ultramarine. Synthetic ultramarine was introduced around 1828 and rapidly became popular. In the sample shown (above) EDXA indicated the absence of the element cobalt in the blue layer: this ruled out both cobalt blue and smalt as the blue pigment. However, both the elements aluminium and silicon were detected. These elements are present in both natural ultramarine and synthetic ultramarine, but not notably in any other blue pigment. In order to differentiate between synthetic and natural ultramarine, which have the same chemical formula, we looked at the pigment grain size: the large irregular grains of the pigments suggested that the blue pigment was natural rather than synthetic ultramarine.
4. Conclusions After removal of the discoloured varnish, it became apparent that the artist had attempted to follow the colouristic intentions of Titian, and may have copied directly from the original rather than from an engraving. The presence of natural ultramarine suggests the picture was painted before 1810, with the coloured preparatory layers indicating an eighteenth century date. Acknowledgements EDXA, x-radiography and photomicroscopy carried out by conservation staff of the National Gallery of Victoria.