As readers, we now know the beautiful faces in magazines have digital help behind the scenes, but we don’t tend to cast the same skeptical eye over Hollywood films.

For the first time, light has been shed on the costly, time-consuming and highly expensive techniques that get your favourite actors looking like pore-less, sag-less superhumans.

In an interview with The New York Times Magazine, actor Paul Reubens (better known by his alter ego Pee-Wee Herman) announced his comeback to the big screen with Netflix comedy Pee-Wee’s Big Holiday – along with the retouching standards he demanded on set.

“Pee-wee doesn’t work, to me, with age mixed into it,” Reubens said.

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“So I knew I wanted digital retouching, and that was my biggest concern from the get-go, with Judd [Apatow], when it came to budgeting, because it costs a fortune.

“I could have had a facelift and we would have saved two million dollars.”

Also this week, Oscar-nominated cinematographer Robert Richardson called for a new Academy Awards category to recognise ‘effects-free’ films.

“It’s just not a level playing field currently,” Richardson said in an interview with The Hollywood Reporter.

“A great deal of what viewers are looking at is not in fact shot by the cinematographer, but is created by artists on a computer and by the director directing them and the cinematographer that’s working hand in hand with them.”

The idea that even a Pee-Wee Herman film would require millions of dollars of retouching certainly raises questions about your average romantic comedy or glamorous period drama.

And according to an industry insider, the practice is far more common than you’d expect.

So what is beauty retouching?

A recent Mashable article blew the secret world of retouching out of the water.

Claus Hansen, a top digital expert from Method Studios in Los Angeles, explained how rampant the process is, and just what gets changed.

“Nobody looks like what you see on TV and in the movies. Everybody is altered,” he said in the shocking exposé.

According to Hansen, studios like his charge anywhere between $500 and $2500 per shot to alter an actor’s appearance, and an actor may appear in hundreds of shots per movie.

Wrinkles are removed, jaw lines neatened, hairlines brought down and even body parts moved.

“One of the most difficult things is if you do too much with the eyes,” Hansen said of bringing actors’ eyes closer together to make them appear younger.

“If you go into Photoshop, move an eye three or four clicks one way – it’s a different person. Eyes you have to watch out for not altering too much,” he said.

Each shot can take up to three hours for the artist to manipulate, meaning an entire film can take up to six months.

Who’s gone under the digital knife?

Aside from Pee-Wee Herman, there have been no celebrities willing to come out and admit to retouching.

But according to Reubens, if you can name a big Hollywood star, the answer is yes.

Bloggers have pointed to Australian actress Margot Robbie’s impossibly long legs in The Wolf of Wall Street, while a Britney Spears documentary was widely criticised for stretching the singer to meet ‘show girl’ standards.

While actors and their managers are careful to keep their digital alterations a secret, certain extreme cases have helped shed light on what the technology is capable of.

Examples include Brad Pitt’s incredibly youthful transformation in Benjamin Button, or Jeff Bridges having 25 years wiped off in Tron.

But while the majority of Hollywood shells out thousands (even millions) on digital retouching, one recent blockbuster has taken a decidedly different approach.

Duncan Jarman, chief of make-up on the set of gory Leonardo DiCaprio drama The Revenant, said the film’s creators were intent on not touching up their actors in post-production.

Of course, that meant a gruelling four hours of make-up per day for poor DiCaprio, who is tipped to take out an Oscar for his performance later this month.