By Neil Smith
Entertainment reporter, BBC News, in Venice
The documentary features actors and stars of the fashion world
The worlds of cinema and fashion collide at this year's Venice Film Festival with a new documentary about legendary Italian designer Valentino Garavani.
Shot between 2005 and 2007, Valentino: The Last Emperor charts what would turn out to be the 76-year-old's final days as head of the fashion house that bears his name.
Packed with celebrity cameos including Elizabeth Hurley, Gwyneth Paltrow and Mick Jagger, Matt Tyrnauer's film follows the designer as he prepares for a spectacular celebration marking his 45 years in haute couture.
But it also offers rare insights into his relationship with his business partner and former lover Giancarlo Giammetti, and their battle to retain control over their iconic brand.
"The film shows me exactly how I am," Valentino told reporters on Thursday afternoon. "I was completely myself from beginning to end.
"Knowing everything was being recorded irritated me a little, but I accepted it. I couldn't care less about the camera."
"We wanted to give Matt complete freedom," agreed Giammetti. "We didn't want it to be a corporate movie.
The film offers a rare insight into Valentino's relationship with Giametti
"There are many things in the film we'd prefer not to see, but they went in nevertheless."
It is possible these include a memorable argument inside Valentino's Rome studio about how many strips of fabric should adorn a white ballgown.
Giammetti's occasionally frosty dealings with the Marzotto family, erstwhile owners of a controlling stake in the company, also come under scrutiny.
Along the way we get to see inside Valentino's glamorous world, a heady whirl of luxury cars, expensive yachts and skiing trips to Gstaad.
And then there are the six pugs that follow him everywhere he goes, one of whom is seen modelling a pair of diamond earrings.
"It was amazing to hang out with Valentino and Giancarlo for two years," said Tyrnauer, a longtime writer for Vanity Fair magazine.
"They were amazing sports and great movie stars. To let our cameras into their lives was extremely admirable."
Julia Roberts wore Valentino when she won her 2001 best actress Oscar
In a career full of industry honours and financial success, it was difficult for Valentino to name a high point.
One thing he says made him "very happy", however, was seeing Julia Roberts accept her best actress Oscar in 2001 wearing one of his creations.
"I saw it on TV and was very excited to see her in my dress," he remembered. "It proved, once more, that movie stars love my clothes."
According to the designer, though, you do not have to be an Academy Award winner to feel at home in one of his gowns.
"I've always loved dressing beautiful women, but over the years I have learned to dress women who are maybe not so beautiful.
"Yet they know how to wear a dress, make it come alive and create a friendship with the garment. That to me is true elegance."
It is those years of experience, claims Giammetti, that have always set the Valentino label apart from its rivals.
Haute couture will never die
"When we met fashion was really at its dawn, especially in Italy," said the silver-haired businessman.
"We built up our empire very gradually, step by step. That's what makes the brand strong - the many years of hard effort behind it.
"The problem with fashion today is that so-called empires are created in a very short time and can be cut down just as quickly."
Valentino, though, remains optimistic about fashion and the "world of dreams" it creates.
"Haute couture will never die," he declares in his native Italian. "Like a beautiful song, it will never go out of fashion."