No, not dirty in that sense. Robert Burden has an unusual hobby. An East End bus driver by trade, in his downtime he likes to draw, mostly portraits of musicians. But he doesn’t use charcoal or pastels or anything boring like that. Robert’s medium of choice? Dirt. Specifically the dirt that collects on vans.

And he’s really quite good at it. Look. Here’s Bob Dylan:

And here’s George Harrison:

Why would anyone devote so much painstaking care to such a bizarre hobby? I had to ask the man himself. His motivations were surprising, and bore witness to a surprisingly sensitive soul.

Where did you get the idea from?

“I’m originally from Exeter in Devon. At school I was into american graffiti and hip-hop. I used to go tagging with friends until I was busted by the police. I moved to London in 2001 and it was a massive shock. So many people and all. I started working as a delivery driver. It was while waiting for jobs to come in that I would practice my drawing. Mainly on paper first. Day to day I noticed the vans would become increasingly dirty through the London air and traffic. I just started to experiment there on the dirty vans, just messing around.

“I went onto the buses to work in 2005. During my time on the buses I had many confrontations with difficult passengers. I found these really hard to handle. Growing up in Exeter I just wasn’t prepared for feelings that surfaced when I was threatened and beaten up by people. I needed an outlet, so I turned to my dirt drawings once more. Going out at night to find dirty vans. I guess it linked into my old graffiti past, the risk one feels doing it.”

When do you do it. Do you have to work by night?

“On the route 15 I have my breaks at Aldgate so it’s then I wander around looking for dirty vans and cars that have come into the city. When I find a dirty canvas I look into my image folder and pick an image that speaks to me, I’m always thinking of slogans and stuff I want to write, like ‘Don’t Destroy The World’ or ‘Human Life Started in Africa’. These are often my political views about the state of society. A drawing can take a good half hour- three quarters of an hour if I really concentrate.”

What happens when you get caught?

“Most people are alright when they discover me drawing on their vans, though one or two drivers don’t understand what I’m doing. It’s not part of their culture, or they just tell me to get lost. The other day in town this bloke was loading metal ducts onto his van. It was nice and dirty so I started to draw a picture of Bob Marley. He said he wanted to smash one of the metal things on my head. “Go and find something else to draw on!!” he said. It was a good drawing, too. That freaked me out a bit.”

Is there anyone in particular you’d love to draw?

“There are many musicians I still haven’t done that I’d like to pay homage to. Growing up was hard and I sought solace in music. Bruce Springsteen and The Beatles were early influences. I’ve got an image of Pink Floyd I wanna do, I’m just waiting for the right moment to come along. I can’t really draw an artist who I don’t care for – Peter Andre, for instance.”

Why do you do what you do? Is there a theme?

“The idea of taking something that is seen as bad and making it beautiful really appeals to me. I guess it relates to the way I feel about myself and my sexuality sometimes. I felt bad, not worthy etc.”

Which drawing are you most proud of?

“I guess the image I’m most proud of would have to be George Harrison, ‘Let It Roll’. I’d been listening to the album all day and I really felt like I connected spiritually with George that day. ‘The Ballad Of Sir Frankie Crisp ( Let It Roll)’ was the main song I was listening to. I was singing it quietly to myself when I was drawing. He was a real inspiration and his views on the world were influential. I kind of felt like he was watching over me when I drew that one.”