Antoine de Saint-Exupery wrote of "Night, the beloved. Night, when words fade and things come alive". But he was wrong. Night time buzzes with chatter. It is saturated with words and with text. Fanzine editors and club night promoters hover outside poky taverns handing out flyers to stripy-stockinged goth girls and their boyfriends. Puffa-jacketed geezers stuff telephone booths with garishly Photoshopped cards advertising the breast sizes and educational prowess of local prostitutes. Flyposting teams armed with buckets of potato paste ride around town in white vans, hopping in and out to stick up A3 sheets about forthcoming tours by young comedians. The radio waves crackle and fizz with the sound of a thousand venomous MCs spitting and freestyling rhymes from inside high-rise council estates.
And then there are graffiti artists. They scuttle through the streets like urban foxes, textual happy slappers ready to coat the city with elaborate spirograms of colour and slanguage, a floetry of illegal form and content. They are, they like to think, artful dodgers, lexical prestidigitators who operate under cover of night. Space invaders, action painters, smash-and-daub pirates, invisible and tersely monikered showmen who have chosen to use the city as a canvas for their rudeboy art. They thrive on danger, regarding the hazards they face and the risks they take before they get to whip out and start spraying their cans of aerosol as a turn on, a necessary precondition of their fugitive scripting.
All of them are addicts. Painting - not just the product, but the adrenalin-rush they get from the process - becomes their obsession. It takes a long time to build up a portfolio and develop a reputation in the capital; they need to plug away with the same metronomic dedication as milkmen or postmen. Only a minority have steady jobs, as the nocturnal hours needed to get their name up in paints means they fall into bed at almost exactly the same time that most Londoners are catching the tube or bus to work. The few who manage to bag part-time positions do so only because it helps to pay for more paints and sprays.
Graffers may like to think of themselves as shadowy lone rangers, cloak-and-dagger textualists, but their social composition, as they will readily admit, is far from heterogeneous. Almost all of them are young men who started out as disaffected teenagers pumped up full of testosterone and a need to vent their inner turbulence, hungry for the kicks or kudos they could get by playing a sophisticated version of Knock Down Ginger.
These aesthetic cherryknockers are mainly white, perhaps not least because the police tend to crack down more heavily on black teenagers out on the town at night. Many are middle-class misfits - bishops' sons, privately-educated graduates, Lloyds' microfiche operators - social autists who find in darkness a confidence and eloquence they lack in daily life.
The greatest buzz is when you've stayed up all night painting a carriage in a station that you've been staking out for ages. The security guards saw you and chased you but you managed to get away from them and hide. So you're there, hiding in a corner, totally knackered but you still really want to see your train. Then when it finally pulls in and it's got the design that you've been thinking and sweating about for weeks - that's lush.
A-Zs mean little to most graffers. They create their own maps of London. They see themselves as metro-rodents, part of a slippery squad of restless voles and tunnel rats who operate according to geographies darker and craftier than those of other city dwellers. They hang around bridges, empty playgrounds, arches full of smackhead debris. They are drawn to the derelict and dingy: broken yards, battered lock-up garages, semi-deserted industrial estates – spaces where they hope to find the time and the peace to paint unhindered by the law.
Abandoned, obsolete London is their fiefdom. No part of the city is antiquarian to them. Over time they build up a vast, working knowledge of its disused train lines, secret tunnels, the catacombs below Farringdon, the shafts at Brixton. They know how to break into buildings, which doors are alarmed and which disabled, how high a drop from a window will be. They ascend higher and descend lower than other Londoners, climbing under fences, shinning up pipes and stomping across rooftops with an ease that seems to ridicule the night's murky light. When they get together, as they occasionally do, they swap stories about pals who were chased by rifle-wielding vigilantes, electrocuted on live rails or had their arms ripped off by oncoming trains. They'll talk about 150-year old sewers that they managed to penetrate, the postal tunnels that M15 operate from Mount Pleasant.
Graffiti artists are speed-orienteers and routefinders. They compare themselves to dyslexics who can mentally rotate the capital in 3D. "We see the city as a shape," says one, "We're always looking at it from above rather than through the dimensions in which we're walking." Theirs is a mutable cityscape, its architecture a set of conundra and challenges to be overcome. They divine ways in and out of buildings. They can gauge the weight of a drainpipe down which to slide. They know that if they cut through an alley and through someone's garden they will end up in the same place they started.
This mastery is not total:
Once we were in West Hampstead trying to climb over the back of this notorious kebab shop that used to poison everyone who ever ate there. It was winter and the place was covered in frost and ice. My mate, who was quite big, walked over some wooden planks near some undergrowth. They gave way, so he fell into a septic tank full of meat cuttings and dripping oil and piss and sick. It was freezing cold too but he still couldn't scream, otherwise we'd get caught. The last time we saw him was running down the road on his own, bits of kebab falling off him.
Graffers are criminals. They wouldn't have it any other way. To legalise their work would be to delibidinalise it. They are willing to stake out a prime site for as long as two months, usually during the winter when they have more darkness to play with, giving up their weekends so that they can lurk like private cops logging the movements and tabulating the itineraries of security staff. They are stalkers, burglars casing a joint, combatants bent on storming military patrol. The language they use for their handiwork - ‘bombing' involves writing your name on as many places as possible; a ‘throw up' is when a long name is abbreviated - conveys the damage and messiness that they wreak.
Uniforms, or any costume worn for working rather than partying, help them stay undercover or invisible. Those who wear the orange coats of railway workers or the bright yellow waistcoats of street cleaners find that no one gives them a second glance. Others don helmets, balaclavas or doo-rags. A melodramatic and health-conscious few wear gas masks to stop them inhaling spray-can fumes that scald their lungs. They'll also come armed with boltcutters, washing-up gloves to protect their hands from give-away traces of paint, and polyester overalls that they ditch easily if caught.
Veteran graffers and taggers don't expect to get caught too often though. Their ears are alert to the sound of police-radio crackle or the distant crunch of Dr Marten'd security officers. And because they are, in however soft a fashion, part of the night's criminal fraternity, they don't feel like victims. They develop neutral walking styles exactly half-way between over-confident flexing and the shaky vulnerability of the drunkard or the homeless. They don't even care about roaring helicopters or the thousands of CCTV cameras festooned across the city. The former, they believe, regard them as small fry; the latter are very often broken or unmonitored – mere ventriloquist surveillance. Karaoke panoptics.
There's a mystery to graffiti that is really appealing. It can challenge your visual sense. You ask yourself how did someone manage to get up that building to write that? There's no drainpipe and no ladders that tall. It's weird. I remember seeing some along the Thames, on the South Bank. I thought it must have been written by someone standing on a boat, but then I found out it was actually someone hanging on a rope off the side of the bank. Even though it was a low tide, he was getting his feet wet all the time he was painting.
The micro-texts that the graf artists create are pieces of ephemeral street furniture that fill the areas where they are found with fragmented reminders of a forgotten history of post-war pop writing: from the KBW signs scrawled by anti-immigrant bully boys and the chads chalked by medical students in the 1950s, through the anti-Vietnam and George Davis Is Innocent slogans of the 1960s and 1970s to the pro-Ocalan or Bin Laden-exalting messages daubed by second-generation ideologues today.
The tags and throw ups, by their very existence as much as by their words or their obsessively rehearsed shapes, are less a dirty protest against modern London, and more a fierce yelp of freedom and straight-to-hell kidult affirmation. They are part of the chatter, the spectrum interference, that city authorities feel obliged to silence. They tattoo the skin of the city; disfiguring or, according to the perspective of the viewer, beautifying it. They say what so many people who work at night would like to shout from the top of Telecom Tower: "I am here."
Graffiti is a kind of fingerprint. Metropolitan police officers have been known to turn up to the opening nights of graffiti-based gallery shows armed with photographs of tags in order to pin down the faces behind the art. Veteran taggers don't need to resort to entrapment; they claim they can read off a biography from most walls. The height of a text betrays how tall the artist is; the slope of the lettering if they're left- or right-handed; the intensity of the spray whether the can has been tilted or held at length.
Ornate styles, those where the tops of letters have a lot of flare, or which effulge with star and cloud symbols, tend to be the work of Europeans. British tags, by contrast, are normally more blunt, less affected: the can is neither pulled back or pushed forward – merely held straight to the wall. London tags are noted for their rawness: almost always simple motifs and on the small side, they are often in black and white as those putting them up don't have enough time for colour. In villages or small towns, it only takes one or two distinctive tags to make an artist's name; in the capital, where competition is fiercer, there is a greater focus on quantity. The art veers towards branding: the shape of the letters, endlessly repeated across the city's buildings, is as important as the words.
Graffers, relentlessly combing the city looking for next surfaces and sites to paint, are keen students of typeface and texture. In their spare time they flick through specialist books and jackdaw the web for images drawn from Mexican wrestling masks, 1950s pulp cartoons, fetish zines and sixteenth-century Bavarian tombstones which they can recycle or recraft for their own designs. At night, when they're not blasting the walls with paint-filled fire-extinguishers, they clock the signs and calligraphies of the city with connoisseurial eyes. They notice, even in dim light, that handpainted storefronts are disappearing only to be replaced by corporate chains that sport logos familiar from television and newspaper ads. They notice that space previously occupied by fly posters and student xeroxes is being bought up by Clear Channel.
Graffers also know, first hand, that London is starting to feel different. Alien to the touch. Electricity boxes used to be green and smooth; now they're stony and spiky to stop them being defaced with marker-pen insignia or stickers. Anyone who brushes against them ends up as grazed and scratched as if they'd just emerged from a playground fight. Other public surfaces have tough vinyl coatings, with the steel designed so that any illegal paint can be easily blasted off.
Some taggers see themselves as playing a cat-and-mouse game with the law and are excited by the challenge of having to hatch new ruses to counteract the emulsifying strategies of local councils. Others view such crackdowns as creative straitjacketing, burgher-pleasing three-line whips designed to snuff out anything messy, random or spontaneous within the city. "All the local authorities have anti-graf squads now," complains one. "Plus they're spending quids on fat forty-year-olds in Japanese vans with high-pressure hoses to rid the streets of chewing gum. Everything is getting cleaned up and buffed out. It's just a different version of them tagging all these young kids and sticking ASBOs on them."
Graffers, whether they like it or not, are part of the urban grime economy, enemies of order. Their art is deemed a fist of defiance. They themselves see, night after night, how the forces of gentrification are encroaching on the spaces that they used to encroach upon. The warehouses and abandoned shops they lacquered with colour are being razed and reconstructed anew. Empty, weeded sites are being filled in. Dark streets are better lit since well-connected newcomers to formerly tough areas hassle their councillors about improving local safety. Graffers, struggling to lurk in the city's disappearing shadows, know that their art is migrating to glassy surfaces and onto the web. They also write in the knowledge that the Olympics will soon obliterate their texts: the Games' organisers, keen to ensure that tourists clap eyes on a gleaming, yacht-white capital, have pushed through zero-tolerance policies that means graffiti disappears within 24 hours of going up.
Once we were on this rooftop near Hoxton doing a painting job. Then all of a sudden this woman who lived over some shops stuck her head out of a window right by us and started shouting: "I know what you're doing." We thought she was going to tell the police and were ducking down. Then she said, "Don't worry. It's cool. But the tiling's not safe. When you finish just come and knock on my window and I'll let you out of the door." We were a bit surprised…
Graffers create liquid architecture, temporary graphic structures that, no matter how much graft or guile has gone into their production, may vanish within hours. Their self-proclaimed works of vandalism may in turn be vandalised by other street-artists playing at one-upmanship. They try to insulate themselves from regret by taking snaps of their work, leaving home in the evening with fresh reels of film in case they get caught by the police who use old pictures of them larking about with their crews to track down and prosecute their friends. A painting is never really complete until it has been shot and entered into the artist's noctographic portfolio.
Some parts of London, however, are cleaned less rather than more often. Artists talk in hushed, reverential tones about a tunnel from Moorgate to Farringdon that contains a huge archive of metropolitan night texts from the last twenty years. Sunlight, even more rain, destroys wall markings; darkness freeze-frames and preserves them perfectly. Wipe away the dust, point a torch at the tunnel wall, and there, for anyone hardy enough to smuggle themselves into this subterranean gallery, are markings and tags written in styles dating back to the dawn of London's urban graffiti scene. They are as thrilling for the graf artist to unearth and behold as prehistoric cave drawings might be to a historian. In the ephemeral world of night writing, these B-Boy calligraphies are almost Palaeolithic.
Walls have appetites. They soak up text, draining it of colour and definition. But this process can take many years. Artists talk of ghost walls on which the outlines of old shapes and designs can just about be discerned. These are rebukes to the aggressive, now-fixated amnesia of some night writers. They also offer the opportunity of applying one layer of text onto another, of creating a tacit dialogue between past and present, a graffiti palimpsest.
Sometimes you get a shock when you see homeless people in tunnels. But they're scared of us as much as we are of them. Mostly it's workers you see at night. If they don't turn their dogs on you, they'll give you a cup of tea and talk about the old days: "When I was your age we'd be throwing stones through windows". Then when you tell them you have to go, they'll say, "By the way, mind you stay off the rail," or "Carry on a hundred yards after that corner, and there's a big bridge you'd like."
Graffers are so used to being labelled vandals that they learn to embrace the tag. They revel in the fact that those outside their circle think of their painting as vomit, artistic flytipping. But they're far from blind to the beauty of what they do or the city on which it is displayed. Summer, though it allows them less hours to paint, is when they go to work in shirts and shorts. They'll carry 4-metre long rollers that they lug up to the roofs of tower blocks and then lean over the side and write their aliases upside down. The fumes stink and soon they feel the twinge of tendonitis.
Finally, just as dawn is breaking through, the job is completed. Their feet still dangling over the edge, they'll reach into their rucksacks for a can of beer or light a joint. They feel a woozy tranquillity and a pride at accomplishing their latest mission. The sun begins to come over London and gently lights up St Paul's, the Gherkin, the Nat West Tower. Below them are the infinite streets and back walls which, as tongue-tied, acne'd teenagers many years before, they started painting to make the girls at school like them. Now, just for a second or two, the city feels all theirs. They smile and nod at this thought. "Nice," they say.