Baby Guerrilla's drawing on a terrace house in Brunswick sits above an example of tagging that is colonising Melbourne's inner suburbs. Picture: Aaron Francis. Source: The Australian

CARS and pedestrians now have a spectacular diversion when they stop at the Upfield line railway crossing on Brunswick Road in the inner-Melbourne suburb of Brunswick.

A few months ago, one of Melbourne's most intriguing street artists transformed a nondescript double-storey wall into a canvas. Previously the space had a riot of graffiti stripped along the bottom, only as high as the tallest tagger could reach. The art school graduate who calls herself Baby Guerrilla pasted high up on the wall an unmissable, 10m-wide line drawing of a boy in flight holding the ankles of a girl who swings below.

Baby Guerrilla's picture overflows with joy and lightness. It is rendered even more powerful by its bold scale and surprising position on the side of an otherwise forgettable urban terrace.

But for all the vivacity that Baby Guerrilla's paste-ups add to Melbourne's streetscapes, across the city there are hundreds of cubic metres of graffiti, the tagging that ranges at its worst from names scrawled with black markers to huge, bright calligraphic pictures.

Just below Baby Guerrilla's Brunswick Road paste-up is a sample of the kinds of graffiti colonising Melbourne's inner suburbs. To some, her work is indistinguishable from tagging, but most municipal councils are now trying to differentiate between street art and graffiti writing, or tagging. Councils want to promote the art -- but in doing so appear to be losing the battle against the graffiti.

In Fitzroy and Collingwood, a few kilometres east of Brunswick, there are some interesting street artworks, including one by Keith Haring near the premises of Circus Oz. But they are difficult to see for the rampant graffiti. Graffiti writers are quick to detect derelict buildings and move in.

The proliferation of graffiti concerns Geoff Barbour, mayor of the local municipality, the City of Yarra. "A number of people have said to me the problem has worsened, which I think is fairly accurate," he says. "There's more targeting of vacant buildings."

Barbour's house has been tagged, too. He says the council spends $500,000 a year providing clean-up kits to households and businesses, and also operates a clean-up service.

"There does appear to have been an increase in tagging, but I want to draw a distinction between art with artistic value," he says. "That's different to people writing with a Texta or spray can."

For decades municipal councils in Melbourne have been grappling with the issue of how to encourage desirable art while protecting the rights of residents and business owners who perceive uninvited decoration as vandalism. The outer Melbourne municipality of Casey has a low tolerance to spontaneous street adornments and school education programs reinforce the council's approach.

The City of Melbourne tries to distinguish between graffiti and street art which, after a battle, it has learned to tolerate -- especially in Hosier Lane, now a popular destination for international backpackers.

Melbourne City spends $1 million a year eradicating graffiti, with a zero-tolerance approach to markings on council property. A couple of times council workers have infuriated artists by removing small works by famous British street artist Banksy.

Some laneways have been zoned graffiti-friendly. Generally property owners are allowed to distinguish between desirable and non-desirable work: they can apply for a permit to have work done on the exteriors of their property or for a permit to retain work already there.

Baby Guerrilla says the problem with the permit system is that it takes too long, and the process of applying for permission is anathema to this kind of art. "I don't know if there's a perfect way of doing it," she says. "It's tricky because artists hate red tape."

Baby Guerrilla was given permission by the Brunswick tenants to do her work on the building, but she did not have the permission of the property owner. Her paste-up, then, is technically illegal. In addition, it was illegal for her to do it so close to a power line.

Baby Guerrilla is governed by laws designed to eradicate graffiti, even though she sees her work differently -- as street art.

"There's a whole different mentality," she says of street artists v graffiti writers who tag buildings. "I'm attempting to enhance the built environment whereas the taggers are anarchists."

In 2010, when Jaklyn Babington curated a street art exhibition at the National Gallery of Australia, she argued there was a continuum from graffiti writers to street artists and within it numerous subcultures difficult to define.

Babington has some respect for graffiti writers. She says it's evident some graffiti writers hone their skills to higher levels. "They call themselves writers because their work is based on the written word or their tag name. You assume a moniker and you write it over and over again and you push it in terms of abstraction," she says.

Babington says the tagging scene references itself, unlike street artists who seek a wide audience. "It's a closed subculture, mostly boys but there are some girls," she says.

There are instances where businesses and homeowners have sought to prevent graffiti by commissioning street artworks. The rules of engagement dictate that artists don't mark pre-existing work but Baby Guerrilla says those rules don't hold in practice. "I aim to inspire people (and) to create a ripple effect, which I believe good art can do," she says. "It can inspire us to strive for more, to be more. Change happens slowly and it starts at the level of inspiration. I don't believe tagging changes anything. Hate just creates more hate."

Babington says it is impossible to make generalisations about either subculture: members of all camps are guilty of occasional transgressions. Taggers often deface street art but the opposite can also be true. Melbourne councils advise property owners to remove work they don't like as fast as possible to neuter the satisfaction of the artist. As with traffic and noise pollution, the other possible solution to urban graffiti is to move to another part of the city, to Casey for example, where street artists are less welcome.