Few businessmen would fill a memoir of their life and work with snapshots of their first snowboarding lesson or the recipe for a favourite pasta dish, but Renzo Rosso does.
He believes snowboarding with his kids and whipping up aubergine pasta sauce for friends are important to the development of Diesel, the Italian clothing company he owns and runs. Indeed, he considers such activities as important as conventional corporate milestones, such as opening the company's first New York store, or selling its six millionth pair of jeans.
Diesel's chairman is one of those entrepreneurs whose personal and professional lives are inseparable. The snowboarding debut inspired the launch of the 55-DSL sportswear range and 55-DSL football team for which Mr Rosso plays. Chatting over a pasta dinner, meanwhile, is his favourite way of ending a working day at Molvena, the once-sleepy village in the Veneto region of northern Italy where Diesel is based.
So far, the formula has worked. Diesel has become an internationally recognised youth brand with annual sales of more than 500 billion lire (£204 million), without forfeiting the hip ethos that fuels its commercial success. Mr Rosso, who, at 43, looks like a New Age wizard with a mop of peroxide-tipped curls, is embarking on the second stage of his company's development with an aggressive retail expansion programme, which may involve taking Diesel public.
He stumbled into fashion by accident. After toying with various teenage moneymaking schemes - from breeding rabbits to playing rock guitar - Mr Rosso enrolled on a clothing production course at his local technical institute in 1970. "I had to do something," he recalls. "And it seemed as good a choice as anything else."
After college, he was offered a job at one of the Genius Group clothing companies, owned by Adriano Goldschmied, in the Bassano del Grappa area of Veneto. Three years later, he launched a new jeans label for Genius, and called it Diesel "because it's one of the few words pronounced the same in every language".
By 1985, Diesel mustered annual sales of $5 million (£3.6 million), and Mr Rosso bought it from Genius. The company expanded steadily in the late 1980s, but its growth accelerated from the early 1990s, thanks largely to a series of self-consciously silly parodies of traditional fashion advertising devised in collaboration with Paradiset, a Swedish agency.
"Other fashion advertisers ran the same monochrome images, the only difference was the brand," he recalls. "We refused to take it too seriously."
The same jokey ethos pervades every other aspect of Diesel: from its pedal pushers and baggy jeans, to the plastic Dalmatian sculptures in the foyer of its headquarters. Everything Diesel does is intended to appeal to young consumers regardless of nationality, because Mr Rosso defines its customers in attitudinal terms, rather than conventional factors such as age and geography.
"A group of teenagers randomly chosen from different parts of the world will share many of the same tastes," he wrote in his memoir. "They may lust after the same supermodel, worship the same film stars."
Diesel's staff is equally cosmopolitan. Mr Rosso scours the world for design graduates - his opening question at interviews generally concerns their star sign - to work in Molvena. "It's fine now, but the locals didn't know what to make of us at first," he admits.
"All these kids with purple hair they thought they were extra-terrestrials."
Fashion companies constantly need to reinvent themselves, and the recruits provide a flow of fresh ideas for Diesel. The company recharges its young designers (average age 25) by sending them on six-monthly globetrotting "research trips", when they photograph or buy anything that interests them.
Like Nike and Gap, Diesel tries to formalise the process of revitalising its stores. Every six-monthly collection is divided into six segments, each of which is shipped to stores at the start of a month to be sold at full price for six weeks and then discounted. "We've learnt a lot from operating our own stores," says Mr Rosso. "Our customers need to know there'll always be something new to buy."
Diesel is continuing to develop new collections, notably the more expensive Style Lab range it will present at next month's London Fashion Week. Yet the main thrust of its future development will be the international expansion of its 25-strong chain of stores, now mostly in Italy, the US and Britain.
Conran Design Group, the London-based retail consultants, is advising Diesel on where to locate the stores and how to execute the opening programme, but its own team will dominate the design process.
"We need to be more professional in the way we open stores, and CDG can help us with that," says Mr Rosso. "But if you buy in creative ideas from consultancies, anyone else can buy them too."
This autumn, Diesel will decide how many stores to open and how to finance them. "If our investment programme is very strong we may go public," says Mr Rosso. "But we'll open a few stores first as a test - we're not crazy."
