AS a 19-year-old he sat at a desk in an industrial estate, putting labels on envelopes and photocopying documents for his father’s manufacturing firm. More than two decades on, he’s sitting on the very same spot, but rather than sticking addresses on mailshots, Paul Savage is leaving his mark on some of the most important records to come out of Scotland.

Savage is the creative lynchpin behind Chem19 recording studios in Blantyre, where acts as diverse as Mogwai, Calvin Harris and Deacon Blue have recorded since the late 1990s. This year marks the 20th anniversary of the operation, which began as the production wing of the Chemikal Underground label Savage set up with his bandmates from John Peel favourites the Delgados.

What started out as a “gang hut” for the band, their friends and other burgeoning acts looking for a place to rehearse and record has now cemented its place in the history of Scottish contemporary music. It’s a long way from afternoons spent photocopying invoices.

“That was the dullest job in the world,” says Savage, who is 44, sitting in the kitchen of Chem19. “I worked for my dad when I was a student, working for a few quid to get myself enough money to buy a couple of beers a week. My desk was right here, in more or less the same spot where I work now, which is quite strange.”

The desk he sits at now is no piece of office furniture. To the untrained eye, it looks like the flight deck of the Starship Enterprise, a bewildering arrangement of faders, buttons, knobs, lights and digital display units. It’s the centrepiece of the control room of Studio One, one of the most important spaces in Scottish music.

The Delgados – guitarists and vocalists Alun Woodward and Emma Pollock, bass player Stewart Henderson and Savage on drums – set up Chemikal Underground in 1994 as a label on which to release their own music, run from a top-floor flat in Battlefield on Glasgow’s south side. Savage, who was studying physics, had been in bands since school but hankered after a career in music, inspired by his favourite group Teenage Fanclub, who hailed from Glasgow and Lanarkshire.

At the height of the 1990s fanzine scene, Chemikal famously signed DIY punk-pop trio Bis in 1994, following with two young bands, Mogwai and Arab Strap. “It was a weird time, when things really started to happen,” says Savage, recalling his apprenticeship as a producer and sound engineer. “I’d done a course at SAE [School of Audio Engineering] in Coatbridge and the attitude was very much: ‘Do it yourself, don’t rely on anyone else.’

“So I went and knocked on doors and one of the doors was MCM Studios in Hamilton, which had opened up in the early 1990s. I made tea until the engineer quit to become a Tupperware salesman. I got the job. We recorded the first Delgados stuff there and I engineered it.”

Chem19 came into being once the boss of MCM quit.

“He decided he’d had enough of working until one in the morning and wanted a normal job,” says Savage. “By that time we’d recorded some important records for the label and it was a really good resource. So it followed from that.”

The name of the studio was inspired by legendary Manchester label Factory’s practice of cataloguing every piece of their equipment, from record releases to office staplers. “We thought that was funny, so we we basically stole it from them,” Savage recalls.

As the label and demand for the studio grew, Chem19 flitted across Lanarkshire from Hamilton to Blantyre, opening on the site of Savage's father’s former business 12 years ago. (The family connection extends to brothers Andrew, who runs Chemikal Underground, and Jamie, who works at Chem19 as an engineer.)

“Before we moved, Teenage Fanclub had come to the old Chem19 and recorded some B-sides. It began to feel that maybe it was a good place. My heroes were coming to record there. But once we moved, it really took off.”

Despite their 20th year, the team behind Chem19 – which is managed by Emma Pollock, a solo artist and Savage’s wife – haven't thrown a party. The only acknowledgement of their floating anniversary was a Spotify playlist quietly released on their social media channels featuring some of the acts who have recorded at the studio.

“It’s against our natural tendencies. We just do what we do and don’t make a song and dance about things,”says Savage. “Putting out that playlist was the biggest song and dance we’ve ever done.”

The playlist is “a 62-track multi-genre monster” and reads like a Now That's What I Call Music compilation of Scottish alternative music from the 1990s onwards: Franz Ferdinand, Idlewild, King Creosote, Camera Obscura, Admiral Fallow, RM Hubbert, Aidan Moffat, Malcolm Middleton, the Pastels, the Twilight Sad, the Phantom Band.

“They’re not all just things I’ve worked on at Chem19,” says Savage. “There’s been a lot of great stuff done by a lot of great people here. But it plays really well as a mix tape, I think.”

He guides me through Studios One and Two, talking me through the rooms and his kit. He speaks with the excitement of a schoolboy showing a friend his toys. There's his Universal Audio compressor (the same model as was used to record the Beach Boys’ Pet Sounds), the Russian Lomo microphone from the 1960s, the 1973 Fender Rhodes piano he drove to England to buy and which recalls, he says, the theme tune to Taxi, and the 30-year-old harmoniser unit he scoured eBay to find for its ability to add a quintessentially 1980s sheen to a production.

Savage rigs up the old 24-track tape machine as quickly as a footballer lacing his boots, and attempts to help me grasp the science behind capturing the emotion first conceived in the penning of a lyric to a piece of tape, with the inner-space magic of magnets and charged microscopic particles. I feel like Charlie Bucket listening to Willy Wonka.

“Mogwai’s debut album is arguably the most important record I ever worked on using really basic equipment and tape,” he says. “But the difference was down to the band. I only facilitated it, I maybe made the atmosphere easy for them. That’s the best I can do.

“My job is to make people feel comfortable enough to expose themselves and their insecurities, constantly telling singers to stop thinking about pitch and start thinking about what they wanted to convey when they wrote the words.”

At the end of the hallway, in a room his father’s operation used for “particle cleaning” of the semiconductors they made, lies the first Chem19 mixing desk.

“The history of that first desk is one I’m really proud of,” Savage says. “The initial idea was to sell it, but then the National Museum of Scotland were talking to us about the label and the studio and what we might be able to give to the exhibition of Scottish music they’re doing next year. I jokingly said they should take the old desk. So they are.”

Recent work at the studio includes a new album from singer-songwriter Rachel Sermanni and the fourth LP from Admiral Fallow.

Savage's nickname among Chemikal colleagues – and Twitter handle – is Chemikal Janitor, on account of the fact that in the label's early days he was always around, but wasn't overly involved in its running.

Twenty years on, I suggest he has become the go-to Scottish producer. Despite what you might read on the sleeve notes of a healthy number of Scottish LPs, such a description doesn’t sit easily with him.

“I don’t feel that way, and I don’t want to be known as that,” he says. “There are connotations there that I hate – the old school guard, the place new music will stay away from.

“When you get to the position when you’re doing big bands you have to be wary of malaise. I’ve always wanted to cater for both.

"I want to do Deacon Blue records, but I also want to do new stuff like Catholic Action. It’s about working with people who are exciting.

“I learn more from bands than I do anybody else. Bands teach me. Arab Strap taught me restraint and simplicity. Mogwai taught me the opposite. Close your mind to trying new things and you might as well be dead.

“It’s about being part of the team rather than being the guy who knows it all," says the janitor, no longer tasked with the photocopying. "I’d hate to be that guy.”