Who, What, Why: How do you graffiti-proof public art?
A landmark sculpture project is at risk because of spiralling costs - including the budget for keeping it graffiti-free. How do you protect public artworks from vandals?
It was meant to be a towering monument - a 50m (164ft) white horse in the fields of Kent greeting Eurostar passengers to England. But now sculptor Mark Wallinger's so-called "Angel of the South" project is at risk because of rising costs.
The price tag for the Ebbsfleet Landmark Project (ELP) has gone up from £2m to £12m, according to reports, with the budget for removing graffiti over 80 years part of the revised bill.
Keeping outdoor artworks like sculptures and murals unsullied by vandalism is a constant preoccupation of local authorities and the hygiene industry. Various types of anti-graffiti protective coatings are commercially available and "target-hardening" - making landmarks more difficult to vandalise - is also an option.
However, some experts argue that a more effective method is to ensure communities feel ownership of their public art.
The authorities responsible for the proposed white horse have good reason to be wary of graffiti. There are many examples of much-loved outdoor artworks falling victim to vandalism.
The Superlambanana sculpture in Liverpool, though it came to be widely cherished in the city, was an occasional victim to graffiti during its early days on display.
In 2010, a newly-restored statue commemorating the struggles for a living wage by striking miners in Tonypandy, South Wales, was defaced with silver paint, causing fury in the community.
And even the apparently impenetrable bronze bull, nicknamed "Bully", which stands outside Birmingham's Bullring centre, was vandalised with an ice skate in 2006.
There are, however, technical solutions for protecting such landmarks.
According to the Anti-Graffiti Association (AGA), there are two types of protective coating that can be used to guard against vandals.
The first are sacrificial coatings, which are designed to be removed with steam or hot water, taking away any paint or ink on the surface along with it.
By contrast, permanent coatings stay in place for years and allow the graffiti to be wiped off them.
The AGA says objects and buildings can also be protected using "target-hardening" techniques, such as lighting, gates fences and anti-climb devices.
However, such techniques would tend to defeat the one of the key objects of public art - that is, to be accessible to the public.
As a result, Prof Lorraine Gamman, of Central Saint Martins School of Art and Design and director of the Design Against Crime research centre, argues that "top-down" initiatives generally fail when it comes to encouraging people to preserve and treasure works of art.
Instead, she says, community-led initiatives are usually far more effective at ensuring that public art is protected by self-policing.
"There are lots of things you can do but ultimately it's about bringing a sense of ownership to the community," she says.
"If you achieve that, the people on the street are the eyes and the ears protecting it."
And, indeed, she says that local people will often become protective of the very graffiti that others might see as a menace.
"Ask the community what they want," she adds. "In Bristol, they protect their Banksys."
Jill Partington, spokesperson for the anti-litter campaign Keep Britain Tidy, concurred with this community perspective.
"When a community respects a piece of public art it is much less likely to be vandalised," she added.
"Prevention is better than cure and an awareness project about the local significance of the art, might have a greater impact on its protection in the long-term."