IT was an unconventional but welcome premiere gift.

Hours before Aardman cofounder Peter Lord presented his new film, The Pirates! In an Adventure with Scientists, a swashbuckling Chancellor had handed the animation industry a tax break in his Budget.

"It is the determined policy of this government," said Mr Osborne, "to keep Wallace and Gromit exactly where they are." Though a joke about Labour's Ed Balls and Ed Miliband, it was also a nod to the animator's place as a British institution on a par with M&S and bad teeth.

The Pirates! cements that place with a voice cast that runs from David Tennant to Hugh Grant. While done in Aardman's trademark stop-frame animation style, The Pirates! adds 3D and computer-generated visuals to the mix, techniques more associated with American animated movies. In short, though it has been doing so for years, and has four Oscars to prove it, Aardman is officially playing with the big boys now.

It's a long way from that kitchen table where Lord and his co-founder David Sproxton decided to give the animation lark a go. "We didn't have any empire building ambition at all," laughs Lord recalling those early seventies days.

The basic set for The Pirates!, based on Gideon Defoe's book, was Blood Island, home of the pirates. Lord's crew built a long, curving quayside, 30 feet long, with 10 buildings on it, each painstakingly detailed and cramming in as many visual jokes as possible.

Once the set was made, Lord began to think beyond its boundaries. What if you could see beyond the quay? What if you could see the sea in all its sparkling, foamy glory? Add computer animation and state-of-the-art visual effects and all that became possible.

"It was so liberating for me. We could make a bigger world, a more spectacular world. It's not showy-offy particularly, we don't do the Hollywood thing. We have three or four ships, we don't have 700 on the screen at once. There's no need for that." He could also have lots of crowd scenes. "It kills you to animate a hundred people in the background."

Though everything is bigger and bolder, it is still unmistakably an Aardman film. "I really feel we're using the best of both technologies," says Lord. "But we never get away from what I think audiences love about stop-frame animation: the sets and the props look incredibly real, believable and tangible, but magical at the same time. I don't know if there's an Aardman style in terms of design, but there certainly is in terms of a commitment to beautiful craft and good sculpting."

So they won't be leaving stop-motion behind? "Absolutely not," says Lord, 59, describing the computer-generated work as "a bonus extra for the audience".

Essential to any Aardman film are the voices. Given that most of the voice work was done in "a miserable old studio in a basement in London", Lord relied on the actors to generate their own atmosphere.

"David [Tennant] was brilliant with Darwin. The animators loved working with his voice because he's so playful, he gave them so much detail to play with."

Unusually for an Aardman film, The Pirates! ran into choppy publicity waters when a trailer was released showing the Pirate Captain (voiced by Grant) landing on a "leper boat" to be greeted by a crew member whose arm falls off. Charities working with people with leprosy complained. The filmmakers couldn't afford to reshoot the scene and time was against them too, so they revoiced it. In the final film, the boat is now a "plague boat" but the arm scene remains.

"We never intended to cause offence. So we thought if that is offensive to a disadvantaged minority then it would be polite to take it out."

You can't imagine Lord setting out to cause offence to anyone. Bearded, bespectacled and wearing black jeans and a patterned shirt, he could have played Richard Briers's kindly brother in The Good Life. Both he and Sproxton were awarded CBEs in 2006 for services to animation.

His sense of humour is impish rather than incendiary, as seen in the Queen Victoria character in the new film. Voiced by Imelda Staunton, this is the monarch as she has never been seen. Isn't Lord worried they'll take the CBE back? He laughs. "Oh they might do, mightn't they? It is pretty damn mischievous, isn't it?"

When Aardman was founded in 1972 their greatest concern was how to pay the rent each month. Their biggest early hit was creating Morph, Tony Hart's clay sidekick. Sensing potential in Morph, they began to think they could do more than just scrape by.

"We thought we'll do a kids' series, we'll make money out of the merchandising and that will run and run and run because we could look and see things like The Wombles and the Mr Men and how they had a 'revenue stream' as they say in business."

Morph didn't work out as a moneyspinner, but Aardman moved on to more shorts then films. Today, it has created a world that stretches from Wallace and Gromit and Shaun the Sheep to The Pirates! and Chicken Run. They are now in their second partnership, with Columbia Pictures and Sony Pictures Animation, after working previously with Dreamworks.

Partnerships with a bigger studio bring a lot to the drawing table, says Lord. They pay for the development of an idea into a script, and they help with the overheads involved in keeping a big studio and a lot of people going between projects. "In the case of The Pirates! they stump up the budget on a handshake. Amazing really." The alternative would have been raising money in Europe, trekking round film funders and slowly drawing together a half or a third of the budget. "The sheer economic power of the studios is wonderful."

I ask if he has seen The Fast Show skit on stop-motion animation in which Charlie Higson, playing the animator, goes through the painfully slow process of putting together a few seconds of animation. It makes stop-motion look marginally less time consuming than tiling the Great Wall of China.

Is it really so painstakingly slow? "Yeeeess, it is like that. I was giving a talk the other day and I found myself saying you move it a little bit and you take a frame, you move it a little bit and you take a frame, because that's how it's done."

But the world of stop-motion is dynamic, he says. Go through the doors of a studio using computer-generated imagery and all you'll see are hundreds of people at keyboards.

"That's how they make films. Whereas what we have is people climbing up on the set, moving lights on scaffolding, big mechanical rigs sliding through the studio, people covered in plaster and paint. Ours is beautifully organic and handmade."

Though the humour in The Pirates! is quintessentially British and silly, he's hoping it will be as much a hit outside the UK, especially America, as here.

"That's kind of in the lap of the gods now," he says, heading off to the premiere. "Rather scary. Hope the gods are in a good mood."

The Pirates! is in cinemas now