The archive at Atelier Brume occupies the coolest room of a converted granary on the hillside above Grasse. It holds some four thousand small amber bottles, each labelled in the same slanting hand, containing absolutes, tinctures and accords collected over three decades. Unusually for a fragrance house, the archive is open. Independent perfumers from across Europe book time to smell it, borrow from it and, occasionally, build rival scents from what they find on its shelves.

This is entirely deliberate. Célestine Maré, who founded the house in 2009 after twenty years composing for large fragrance manufacturers, believes the industry's obsession with secrecy has made it poorer. When she started out, young perfumers could spend years without smelling a genuine rose absolute, because the good materials were locked inside a handful of corporate laboratories. She wanted to build the opposite: a house whose value lay in its generosity rather than in what it could withhold.

It sounds like a charitable foundation, and Maré is quick to insist that it is not. Atelier Brume sells eleven fragrances under its own name, supplies bespoke compositions to a small number of hotels and restaurants, and runs a training programme for which students pay handsomely. The archive, she argues, is the house's best marketing. Everyone who visits leaves with a story, and many of them return as customers, collaborators or employees.

Leadership by the nose

Her management style is similarly unorthodox. There are no job titles at Atelier Brume, only apprentices, perfumers and what Maré calls keepers, the three senior staff responsible for the archive, the finances and the garden. Decisions about new fragrances are made by blind vote after a week of smelling trials, and Maré's own vote counts for no more than anyone else's. She has been outvoted, she says cheerfully, on four of the house's eleven scents.

A secret keeps its value for a season. A reputation for generosity compounds for a lifetime, and it is much harder for anyone to copy.

The approach has limits. Growth is slow, and Maré admits that several promising perfumers trained at the house have gone on to compete with it directly. She has also turned down a series of acquisition offers from larger groups, each of which would have required closing the archive to outsiders. The house employs nineteen people and has been profitable for eight consecutive years. Maré regards both numbers as about right, and has no intention of changing either.

On the morning I visited, a young perfumer from Copenhagen was seated at the long oak table, dipping blotters into a flight of vetivers and writing notes in a tiny, furious script. Maré brought her coffee without being asked and pointed out, gently, that she had missed a bottle from Haiti on the lowest shelf. The young woman thanked her, then asked whether she could return next month. Of course, came the reply, the archive is always here.

It is tempting to read Atelier Brume as a quaint exception, a craft business sheltered from the pressures facing larger companies. But Maré's wager, that openness can be a durable competitive position, is one many industries are now testing in their own ways. In a field built on mystery, she has made trust the most valuable ingredient in the building. It is not listed on any of the labels, but everyone who visits seems to smell it.