Keira Knightley admits it took 45 minutes to paint on cleavage for Pirates of the Caribbean role

Keira Knightley would have been better off getting a painter and decorator rather than a glam squad to help her transform into her Pirates of the Caribbean character.

The London-born star, 39, starred as the strong-willed Elizabeth Swann in the swashbuckler franchise, alongside Johnny Depp and Orlando Bloom.

And although she embodied effortless beauty on the big screen, Knightley revealed that a lot of hard work went into her appearance behind the scenes.

As well as the usual hair and makeup routine, the Oscar-nominated actor revealed that she had to sit still for three-quarters of an hour while someone 'painted in' her cleavage.

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During an appearance on Late Night with Conan O’Brien back in 2005, Knightley excitedly discussed how she was reprising her Pirates of the Caribbean role.

She told the US talk show host that the cast were having 'good fun' while shooting the two sequels to The Curse of the Black Pearl back-to-back.

Although she explained she'd had a 'fantastic' experience so far, Knightley admitted that she had one small thing to moan about.

But it wasn't the long hours on set or remembering her lines, as she explained: "I'm a bit disappointed because in the first one, I got my cleavage painted in every day."

Keira Knightley revealed her cleavage was 'painted on' in the 2003 film (Gareth Cattermole/Getty Images/Disney)

The mum-of-two revealed that a 'very nice lady' would come and 'paint her a cleavage for 45 minutes every morning' before a day of filming as Elizabeth Swann.

Explaining the purpose was to emphasise her bust, Knightley said: "It's very clever, it's shading and everything."

Although her character often donned a corset in the first film, the actor said Elizabeth had a different sense of style in Dead Man's Chest and At World's End.

"In this one, I'm not really wearing a corset," Knightley said. "I like the costumes a lot, I do like corsets. They make you stand up very straight."

She also praised the unknown artist's cleavage painting skills during an appearance on The Graham Norton Show in 2014.

The actor was just 17 years old when she was cast in the Pirates of the Caribbean franchise (Disney)

According to Knightley, the 45-minute ritual was the 'best bit' about starring in Pirates of the Caribbean when she was just 17 years old.

"It’s great," she laughed. "I’ve got very little up top, so it took 45 minutes to hoist up what I have got, and then paint in the rest.

"They looked amazing!"

The Love Actually star might have enjoyed this aspect of starring in Disney's pirate franchise, the role also took a major toll on Knightley too.

She previously revealed she needed 'many years of therapy' to cope after she was catapulted to fame, while also discussing how she was 'stalked by men' after her hugely successful Hollywood debut.