Imagine deciding to make a film about a six-year-old boy growing into a man. And just to keep it authentic, filming it for one week each year for 12 years, so the actors age naturally on screen and bring their own experiences to enrich the characters they play. It sounds like a tough pitch to approach Hollywood studios with. But this didn't stop writer-director Richard Linklater making Boyhood with the same group of actors.

Filming started in 2002 and wrapped in 2013. The actors were invited to collaborate and workshop with Linklater throughout the process as they matured alongside their characters.

The result is remarkable. Boyhood is a fictional drama that expertly shows the highs and lows of a boy named Mason, played by Ellar Coltrane, as he faces life's challenges in a broken home in Texas. There are many subtle moments that elicit Mason's joy, hope, hurt and disappointment as he grows up with sister Samantha (Linklater's daughter, Lorelei) and struggling single mum Olivia (Patricia Arquette) as Mason Sr (Ethan Hawke) comes back into his life after returning from Alaska.

Making Boyhood was an extraordinary experience for Arquette, who managed to juggle diverse television roles as psychic-crime-stopper Allison DuBois on Medium and ballsy-bootlegger Sally Wheet on Boardwalk Empire during the film's production. The 46-year-old initially sounds tired as she greets me on a call from her home city of Los Angeles but comes to life as soon as we start talking about the film.

"Nobody else would have made this movie except Rick (Linklater); nobody else would have made it like that; nobody else would have told that story like that," she says. "Somebody else's ego would have gotten in the way and they really would have f----- this movie up, I'm telling you, in a thousand different ways."

Boyhood can be categorised as a major commercial success. With a budget of $4.42 million, it has grossed $32.41 million worldwide and counting, according to Box Office Mojo. This has been fuelled by the glowing reviews and plaudits it has received at festivals around the world, including the Silver Berlin Bear for Best Director, SXSW's Louis Black/Lone Star Award as well as being nominated for the Sydney Film Prize. Arquette herself received Seattle's Golden Space Needle Award for her portrayal of the unlucky-in-love mother.

Backing came from independent film supporter IFC Films, whose president had to fight an ongoing battle to keep it in production over the 12 years, Richard Linklater said in a production statement. "He had to explain every year what this expenditure was and why there wasn't going to be anything to show for it for more years to come. I was lucky to find that, because otherwise this would not have been possible." 

Having a smaller budget meant there was less interference for the filmmakers to follow their vision but, Arquette says, it was not the key factor that enabled Boyhood to be a success.

"It does help but it really comes from the filmmaker – it doesn't matter if it is a $10 budget, if the filmmaker is like strangling everyone else's contribution, there is not a lot you can do about it," she says. "And I've been in that situation before. I've been really f----- over on art movies before."

For her, Linklater's collaborative approach brought out the best in the actors and helped enrich the characters. The 54-year-old writer/director started with a framework for the story and before filming each year, the actors would help him fill in the details. There was cross pollination of experiences and backgrounds for each character, she says.

"There wasn't a script to begin with but there was a strong architecture and that all stayed the same: I would go back to school, I would get remarried, I would get divorced," Arquette says. "Ethan's character had different changes and the changes the family was going to go through – all that remained.

"The specifics about what we … were going to say every year, Rick would write that just before we'd shoot that year. Then we would go there and workshop it and improvise and talk about life experiences we had in our family … and then Rick would take moments of all of those things and then rewrite it.

"There were all these weird crossovers like Rick's mum and my mum had gone back to school and had become teachers and gone into therapeutic sciences. Rick and Ethan's dads had gone into insurance businesses and had second marriages but Ethan knew at the beginning he wanted to be the guy, the wild musician guy driving a GTO, and in the end he wanted be the guy driving the minivan wearing a cheap suit."

There are also similarities between Arquette, a Chicago native who has a 25-year-old son and 11-year-old daughter and who has been divorced twice (first Nicolas Cage in 2001 and then Thomas Jane in 2011), and her character's journey. While the actress can identify with the single mum who battles through three broken relationships while raising her children, working and pushing herself through university, she is not a facsimile.

"I mean, she's not me for sure – there are a lot of differences that we have, but I also can identify (with) her," she says. "Parts of her are close to me, parts of her remind me of my mum or my friends or different things.

"You know, it was such a big collaboration, there would be parts of Ethan's mum that would be in there and parts of our producer and parts of all these different people and that went across the board with each character."

Given the organic nature of the production and logistics of juggling everyone's busy schedule, there was pressure to come through in the narrow window the team met for filming each year, she says.

"We all had a similar way artistically of looking at work and we also committed ourselves but also we knew we had to nail it," she says. "We had very little money, we had to get what we needed to get every year. There was a lot of shooting every year for a very modest budget and there was no going back and shooting because the kids are going to get older."

Richard Linklater took many risks with Boyhood, according to Arquette. 

"There are so many aspects of this movie that are completely untraditional, and in a weird way the most minor one is the fact that it is shot over 12 years," she says. "Rick chose to tell this movie in a non-traditional dramatic sense," she says. "Usually, you know, there is a formula that you tell a movie with and he threw all that out the window."

Another was his choice of Ellar as a sensitive, introspective, observant child as the lead, she says. 

Boyhood is a coming-of-age movie without the obvious sign posts, too. Linklater did not want to demarcate the first time you drink, the first things, the most obvious things, Arquette says.

"He threw a lot conventional wisdom about how you tell a movie out the window, which is incredibly brave to do."

Watching the finished product was a surreal experience for Arquette as each scene reminded her of what was happening in her own life during that period.

"'Oh right, that's when I think I got married, that's when Ellar's parents split up, that's when I had my daughter'," she says. "Yeah it was a weird combination, watching it the first time it was like watching it with three different brains. The character was watching the movie for the first time … and then there was me knowing our real life off camera and me as an actor watching it – me as an actress watching myself grow and change."

Of course, the success of the film rests on the young shoulders of Ellar Coltrane. The story is told through his character's eyes. Linklater – a promising high school baseball player who chose filmmaking over pursuing a career in sport – wanted his lead to have some experience performing on camera, which Coltrane had already accrued by the age of six. He also wanted the young star to go through life experiences before acting them as Mason, Arquette says. The director chose well – watching Mason/Ellar grow on screen into a man is seemless and natural.

However, Arquette was worried with the spotlight on Ellar Coltrane for so long and with him growing up on screen in a way that has never really seen before, how the young star would handle the release of the film as critics and audiences responded to it.

"I feel like the most fragile moment was really finishing it," she says. "Letting a movie come out, suddenly it becomes a whole distortion in the world and that's the weird part of it. That's the most vulnerable part of it and that's the part that I was most worried about."

"How – to have this intense focus on you, especially because people saw you grow up in a way they've never really seen somebody else grow up– how is that going to be for them? But Ellar has really dealt with it with this incredible grace and beauty."

Perhaps it also helped him to have the support of some very experienced screen parents, too.

"In the course of his doing publicity he ended up in LA and he stayed at my house and I did wash his underwear," she laughs, "I guess art imitates life!"

Boyhood is in national release. Rated M.

smh.com.au