Shaun the Sheep Movie: secrets from the set

The whiteboard says it all. Written inside an ink drawing of a fluffy-looking sheep, are the words: "Shots until the end of the film: 427." Not that there's any sense of panic - not yet, anyway. On the last day of July, the production of Aardman Animations' Shaun the Sheep Movie is ticking along nicely. "You're never on track - that would be too easy," says co-director Mark Burton. "But we're not far off. Stress levels are pretty good today."

As you might expect from the company behind the beloved characters Wallace and Gromit, humour is the order of the day. On one wall is a picture of the grizzled Quint character from Jaws next to the phrase "Don't muck with the Art Department!" In the model-making room, there's a poster for a Kickstarter campaign to "Bring Back Morph", Aardman's little brown clay figure who became a staple of 1970s British children's television.

Founded by David Sproxton and Peter Lord in 1972, Aardman has set the gold standard for British animation with films like Chicken Run (2000) and the Wallace and Gromit movie The Curse of the Were-Rabbit (2005). Over the years, they've won four Oscars - although nobody is boasting. Lord, a bearded, avuncular 61-year-old, who looks like your favourite uncle, is as low-key as the Aardman building, housed on an anonymous business estate on the outskirts of Bristol, England.

Yet it's here where the magic happens. "Performance is the thing we love here," Lord says, when he ushers me into a screening room to watch clips from the Shaun the Sheep Movie. Behind him is a picture of Shaun, sitting by a pool, reading a screenplay, with "The Birds" crossed out and replaced by the title "The Sheeps".

It is, of course, another Aardman gag. "There's not a lot of Hitchcock in there," Burton tells me, although film influences are still strong and feature everything from Jacques Tati movies to Ferris Bueller's Day Off.