You observe, punctuate a scene with colour, accentuate things, compress moments together and capture a vibrancy to create a bigger image that you just can't do with a photograph. There are two camps in illustration at the moment: the paintbrush and gouache set who paint to board and the ones who use a Macintosh Some do both. Many were resistant to computers at first: even three years ago they'd say "don't mention the Mac to me", but now many are moving in that direction There is a notion of the craft changing Computers can certainly help the turnaround process. We can say: "We need this new submarine rendered by tomorrow." They can e-mail it the next day, when the process used to take three days. But board is wonderful - you can use other media to add to the image - and it's exciting getting a FedEx package still.And, of course, we're amassing a huge collection of original artwork that we can hang on the walls in our new offices.Gas station on Houston and Lafayette Street"I painted this at night, and it took about two hours, standing up, resting my board on a bollard. I had been on my way home and suddenly came to that corner and saw a fantastic view; Houston Street is wide, and at night the car wash looks like a fairground, and the taxi was sitting there like a big slug. I've developed a shorthand over time - for example, the way to draw a traffic light, a subway entrance, a kerb, a phone booth.

You see these motifs repeated, all over the city, so much so that people say it looks the same. While you're painting, you notice little vignettes made up of familiar elements."The New York Stock Exchange from the Federal Hall steps"This was the day after a major financial panic, and gangs of news crews were there, interviewing brokers about their lucky escapes. Everyone was going, `Hey, I didn't lose anything.' I like the way the reporters stand on a box so that their faces make a nice composition with the building on the monitor. This was done from the steps of the Federal Hall, slightly away from the action. I like being a surreptitious observer - in some ways, it's the best thing. This afternoon was very cold, and you can only draw for 45 minutes then you have to get up and get warm."this51st Street and 6th Avenue"I love the abstract nature of the title of this building - I wanted everything else to be less specific. For the painting I was sitting almost on the road: I map out a drawing quite roughly and then just start the real thing.

By occupying a small part of the street for a while, I have noticed the city in a new way. There is a small independent world of people who know each other - cops, pretzel sellers, donut vendors, hawkers and street sweepers - on each patch. All around, everything else is in perpetual motion, but their territory is fixed, and by stopping there I too became part of the group and was looked after. In this way New York has never seemed overwhelming or inhuman to me."Officer Reilly and his horse Cannon"Cannon is named after a murdered policeman. Reilly was on patrol on part of 47th Street (the Hatton Garden of New York). Apparently a horse is a great deterrent against diamond thieves. He is there for two hours, until the horse gets restless, at which point he moves over to another street near the Rockefeller Center.