'Check where I am!' says Fran Healy, turning his screen to show the stunning blue skies and desert of the Joshua Tree National Park. He looks the very definition of contented, sitting on a porch with some coffee. 'I'm in Maryhill,' I offer drily. 'That's where I'm from!' he replies, beaming. Healy's a positive guy; the kind who would ask a music journalist who doesn't like his band of over two decades to co-write and appear in a documentary about them, and from that unusual scenario visualises an endgame that's not just amicable but that permeates warmth.

Wyndham Wallace is the aforementioned critic who Healy first encountered when both were living in Berlin. 'He came up to me on a night out,' says Healy, 'and just said, "you're that guy from Travis: I really don't like your band." He just came straight off the bat and said it. I mean, nice to meet you too!' Did Healy not think he was a piece of work? 'He's very posh and it was his idea of an icebreaker: "listen, this is what I think so I want to tell you straight away". I get that a fair bit, it wasn't something that hadn't happened before.' He raises his mug to mouth, eyes fixed on the landscape, adding, 'I thought it was quite charming.'

As well as providing some insight into the dynamics behind one of the most successful Scottish bands of all time, Almost Fashionable takes a look at what it means to be a critic, what it means to be a fan, and where the lines get blurred. Healy and cinematographer Cristian Pirjol, (who worked together on a short movie to accompany the band's last album, Everything at Once) had discussed the idea and, sensing a documentary project needed to offer a fresh angle, came to the conclusion that Wallace could help out.

'We thought rather than the usual "get someone who's a fan of the band", to get someone who wasn't,' says Healy. 'The main thrust of it was that here we were, 20 years old as a band, still together and very much in love. I wanted to take an honest picture of us. He was the guy. I think he probably realised he'd spent so much time being a critic that he forgot what it was like being a fan. If you're a journalist, this is your business. You don't so much get cynical as see behind the curtain. In a funny, perverse way I hoped he might realise something like that: and he did.'

Almost Fashionable certainly exposed Wallace to some hardcore Travis fans in their 'home from home' of Mexico, which won the contest to be the film's setting. 'They have a similar thing to Glaswegians in that they don't hold back if they're at a show,' Healy enthuses. 'They just have a really good night and get into it. The people are so cool and I've never met an evil Mexican. I've never felt threatened or encountered that. It must exist; you watch El Chapo and read the news but, touch wood, I've never encountered it.'

The critical angle of Almost Fashionable is pertinent to Travis. The band will spend much of 2018 on the road, performing their multi-platinum selling second album The Man Who. Released in 1999, a slow start gave way to ubiquity after a memorable Glastonbury performance when the heavens opened during 'Why Does it Always Rain on Me?' By the year's end, only Shania Twain and Boyzone had shifted more units in the UK. Critical reception on its release was mixed.

'I remember turning to Dougie [Payne, Travis bassist] and going, "fucking hell man, this is a really good record". Then the reviews come in and they're terrible. I think critics thought they were going to get another Good Feeling [their 1997 debut], that rock, romp, Oasis glam thing and we (not deliberately) delivered something more contemplative, parochial and autumnal. I remember sitting with all the newspapers laid out and it was terrible. We thought we'd have to pack up and call it a day but, out of the blue, it just went mental. It taught me a big lesson: you never really know what's going to happen.'

Is Healy bitter about the negative words? 'I used to get really wound up by it,' he concedes, 'because you'd spend ages making something and do the best you possibly could and some guy would say, "that's fucking shit!" After a few years you realise a lot of show business, even on the critics' side, is just pantomime and you learn to take the blows.'

Healy is excited to see the reaction to Almost Fashionable, but glad an intricate job has been applied to it. 'There's just so much involved in it that's unseen,' he says. 'When you say, "let's do this, this is a good idea", you don't think about being in an editing room for a year and a half. I've been dying to write some songs!' I leave him to the California heat, alone with his creativity, free of critical appraisal.

Almost Fashionable: A Film About Travis screens as part of Edinburgh International Film Festival at Cineworld, Fri 29 Jun, 9.15pm; Odeon, Sat 30 Jun, 8.40pm.