Female friendship is the focus of many a film that hits our cinemas.

And that's what is at the core of coming-of-age drama Balance, Not Symmetry, from filmmaker Jamie Adams (it was made in close conjunction with Scottish band Biffy Clyro).

Part of the appeal for stars Laura Harrier, 29, and Bria Vinaite, 26, was how it depicts that in your 20s "the most important relationship in your life is that with your best friend".

"It's rare to see. These girls really love each other and they're each other's most important relationship - it doesn't have to be romantic in order for it to be important," notes Chicago-born Harrier, who's also starred in Spider-Man: Homecoming and BlacKkKlansman.

The friendship isn't without its issues, of course. But in the end, they get through them together, and "realise they have each other".

"I think in most movies, if she'd have slapped me, I'd have stopped being her friend - but that didn't happen," Lithuanian Vinaite - known for her role in comedy-drama The Florida Project - notes with a smile.

So, we know there's a slap scene: "The first few takes, she was doing it so light, that by the third one, I literally screamed at her, 'Slap me for the sake of art, Laura!'" recalls Vinaite, and they both laugh at the memory. "It was really funny."

But what else can we expect from Balance, Not Symmetry?

Well, it centres around Shirley-Caitlin (Harrier), a Scottish-American art student studying at Glasgow School of Art, whose life is turned upside down when her father unexpectedly dies.

She decides to finish her third-year studies after the funeral, leaving her grieving mother behind - but struggles to deal with her own sense of loss.

Trying to regain balance in her life, she finds inspiration from provocative fellow student Hannah (Vinaite).

Discussing why these characters felt right for them to play, Harrier suggests: "First and foremost, our relationship with each other was really the foundation of this film, and finding these characters was about these two girls finding themselves through their friendships and the trials of their lives.

"And obviously, it being improvisation-based, a lot of our self is in it, but I think we're both still definitely playing characters - this isn't a documentary about being Laura and Bria.

"It was, I think, some of our own life experiences influencing these characters. You know, dealing with loss, and dealing with this friendship..." she elaborates softly. "Emotional things through a creative output."

"Just being there for a friend when they're going through something, even if you might not necessarily understand why it's taking so long," follows Vinaite.

"Everybody deals with grief differently and you just have to be a good friend through it."

The pair share having each other's support in real life helped them get through what was an intense shoot across various locations in Scotland.

"I definitely was a little homesick, for food and for weather," confides Vinaite, who now lives in the US.

"Because it was really cold when we were there. And I missed hot sauce. We bought all the sriracha they had at Sainsbury's."

"They only had three bottles and we bought all of them!" chimes in Harrier.

Not only is Balance, Not Symmetry a moving piece of cinema, it also pays tribute to Scotland (particularly Glasgow), and its art and music.

Interestingly, as well as writing the score for the film, the lead singer of Scottish band Biffy Clyro, Simon Neil, worked with Adams on the script too.

"I think it's really special when a whole soundtrack to a film is done by one band - that doesn't happen often," notes Vinaite.

"Going into it, I was really excited knowing it was all going to be a cohesive piece of work... Each song represents the scene that it was on, which is really rare."

The project definitely presented a totally new and different challenge for this lively, fun duo (they bounce off each other really well during our chat, with lots of giggling), who no doubt both have exciting careers ahead of them.

Harrier has just finished shooting a sci-fi film with Tom Hanks, called Bios, which is going to be out next year.

"I love doing big budget movies and having fun with that," she says, "but then it's awesome to be able to do something like this that's a bit more artistic and creative, and it's really good to have an input in the story and collaborate with people."

Vinaite, meanwhile, is currently busy making her own animated show: "It's going to be a comedy, but will talk about important subjects like mental health, identity and struggles."

There's a lot of discussion at the moment about how this is a really progressive time for the TV and film industry.

Do they feel empowered knowing there is, perhaps, more opportunities and variety, when it comes to roles for women now?

"Yeah, sure," says Vinaite emphatically. "I also think it's a really special time because way more women are getting into different positions than they have been.

"I'm creating a show right now - I'm producing it, I'm in it, and I feel like learning all the different elements of everything else that happens is so interesting, and it makes me so much more passionate about creating. And the fact that, finally, more women are in these roles, and we could get even more, it's a really great time to be an actress."

"What's so important as well is to have women not just in front of the camera but behind as well; directing and producing and writing," Harrier concurs.

"That's how more people's stories get told."

Balance, Not Symmetry is in cinemas now