Cleaning controversies  regarding poor attempts to restore artefacts are not new – the Parthenon Marbles attracted similar attention based on problems caused by the treatment of the sculptures in the 1930s.
The Art Newspaper 
European treatment harms African works?
Questions are being raised about a protective coating applied to Ife sculptures
By Martin Bailey | From issue 223, April 2010
LONDON. African art specialists are questioning the recent conservation of Ife sculptures in Madrid in preparation for an international touring exhibition. They are concerned that Spanish conservators applied an inappropriate coating intended to protect the sculptures during the tour and after they are returned to Nigeria, and might even have removed ancient surface patina.
John Picton, a professor at the University of London’s School of Oriental and African Studies and former deputy director of the National Museum in Lagos, says that the ancient brass heads have developed “a shiny surface”. Other specialists have also expressed concerns about the treatment by conservators at the Instituto del Patrimonio Cultural de España (Spanish Cultural Heritage Institute).
“Dynasty and Divinity: Ife Art in Ancient Nigeria” includes some of the finest sculptures ever produced in Africa. It is the most important show ever mounted about Ife culture and is now at the Virginia Museum of Fine Arts (until 22 May). Last year it was at the Fundación Botín in Santander, the Museo de Bellas Artes de San Fernando in Madrid, the British Museum and Houston’s Museum of Fine Arts.
Pre-conservation condition of the works
Before their conservation in Spain, the Ife sculptures had not been well cared for in Nigeria, where conservation and storage facilities are generally inadequate. One important aspect of the international tour is to generate funds and offer training opportunities for Nigerians—when the exhibition visited London in 2010, conservators from Lagos were involved in the installation of the show.
When the sculptures were first shown to the curators of the touring exhibition, some of the finest pieces were brought out and placed on an inappropriate piece of foam on the floor of the National Museum in Lagos.
Some sculptures had spatters of modern white paint—consistent with the type used on gallery walls. Most of the works in the exhibition catalogue were photographed before conservation, and a granite figure of a crocodile has traces of white paint visible around its front foot (cat 12). Some stone sculptures had been displayed out of doors in Ife, including a very tall stylised shield and a sword (cats 9-10). These had been buried in a courtyard of the museum, as they would have been traditionally. A finely carved figure of the gatekeeper deity Idena, possibly 12th century, had been cemented into a plant pot to provide a display stand. It was shipped in one piece to the British Museum, where the planter was safely removed (cat 8).
Dating from the 12th to 15th centuries, most of the 100 pieces had never left Nigeria before. In 2009 many of them were sent to Madrid for conservation. Although the Instituto del Patrimonio Cultural de España’s conservators are highly respected, they have had relatively little experience of West African art.
Among the most important Ife loans are 20 heads and figures in copper alloy (brass), and these are the sculptures that have generated most concern. Surface wax, which had been applied as a moisture barrier at various times in the 20th century, was removed, which may have led to the loss of any original surface coverings from antiquity.
After cleaning, an anti-corrosion inhibitor, Benzotriazole (BTA), was applied, but this has the effect of making metal appear shiny, particularly under direct lighting. The BTA coating protects the brass from humidity. But, critics say, more consideration should have been given to environmental conditions during the tour and in the National Museum in Lagos (where the works have mostly been kept in recent years, following a spate of thefts at the Ife museum).
On top of the BTA, Spanish conservators added a layer of Incralac, an acrylic coating for copper alloys that dulls the surface. This coating tends to dissipate with handling, although it can be reapplied.
The Instituto del Patrimonio Cultural de España says the treatment is “easily reversible”. It also believes that the visual impact of the sculptures “stayed the same or was improved”.
All the conservation work was approved by Nigeria’s National Commission for Museums and Monuments, which owns the collection.
Mayo Adediran, Nigeria’s director of museums, stresses that BTA is a protective coating. It does not affect the metal, its effects are reversible, and he believes the “best options” have been taken to conserve the sculptures.
But he added: “If it turns out the objects have a ‘shiny surface’, it calls for a further investigation on the quantity and mode of application of Incralac on the BTA. We shall carefully look into all complaints and find solutions if they are necessary.”
Enid Schildkrout, the New York-based curator of “Dynasty and Divinity”, has looked again at the conservation process. She said: “I am quite certain there has been no damage. The appearance of the sculptures may have changed with the various treatments, including the former applications of waxes and the BTA coating, but it is important to protect them from humidity. Whether a shiny surface matches the intentions of the makers is an interesting, but probably unanswerable, question. It’s a matter of taste, and raises the question of whose taste: that of the maker, the owner or viewer.”
The show, “Dynasty and Divinity”, travels to the Indianapolis Museum of Art (8 July-15 January 2012) and to New York’s Museum for African Art in 2012