Hundreds of volunteers have stripped naked for a public photo shoot marking the 10th anniversary of the Lowry art gallery in Salford.
Spencer Tunick is photographing the models in eight different locations across Manchester and Salford.
Tunick's aim was to capture the movement of everyday people and reflect the work of artist LS Lowry.
The photographs will be part of an exhibition at The Lowry gallery - which is named after the Salford artist.
Tunick has photographed thousands of nude volunteers across the world, most recently at the Sydney Opera House last month.
But this project, involving a total of 1,000 naked people, will be the New York-based photographer's first multiple site installation.
He told BBC Radio 5 Live that he had been inundated with requests to join the project.
"I think I have done enough works in England where there's sort of acceptance of my work as an art form and people really want to pose," he said.
"I mean, we had people signing up to do this, and so we had to get that number down to 1,000. It's taken me about 10 years to gain the trust of the English public."
Victoria Denning, from Birmingham, said taking part was a "great experience".
"It's wonderful how many different shapes and sizes of bodies there are," she said.
"You get so used to seeing a certain shape of body in magazines, and not one single person looked like that.
"Even the first time it felt normal because everyone was doing it and nobody was looking. It was just amazing."
Sean Hayes, 28, from Cheshire, said he volunteered after seeing Tunick's work in Sydney.
"I'm normally very shy but I wanted to come to this. You've just got to take the plunge.
"All you had to was look around and realise you were part of something really special."
Over Saturday and Sunday, 500 volunteers will be taken each day - via heated buses - to the eight secret locations and asked to pose naked while Tunick creates his piece of work.
Four locations have been chosen for each day.
The volunteers are all of different body shapes and sizes.
Michael Simpson, from The Lowry, said: "I think Lowry would really like it because his whole mission for him was to paint ordinary, everyday people going around their daily lives.
"The people who feature in this project are doing something extraordinary, with no clothes on, but they are just ordinary people, all different colours and shapes and sizes.
"He would like the fact that it is not high-brow or pretentious, just ordinary people. He would be amused, even a bit bemused probably."
Much of Laurence Stephen Lowry's art is characterised by matchstick figures and industrial landscapes and his work is often sold for millions at auction.
The gallery in Salford houses the world's largest public collection of his works and Tunick said he was inspired to begin this particular project after visiting the gallery.
His work will be on show as part of the Everyday People exhibition, on show between June and September.
Tunick said he was also looking for volunteers to take part in his next project at the Big Chill Festival in Herefordshire.