PARIS, France — Alexandre Mattiussi arrives on a scooter carrying a big suitcase in what looks like a very risky position. "I just got back from the factory and I'm exhausted," he says with a big smile while climbing up the stairs to his showroom. Seated on his balcony, someone screams below: "Alexandre! Comment tu vas?" It's the grocer opposite and the two exchange a few words with a laugh. This is as down-to-earth and amicable as it gets, which exactly captures the simple idea at the heart of Mattiussi's affordable luxury menswear brand, appropriately named Ami.

"I like the idea of dressing as many men as I can," says the designer. And, with 40 new points of sale planned for this fall, bringing the total to over 120, Mattiussi — who previously worked at Dior, Marc Jacobs and Givenchy, where he and a colleague headed the men's line for two years, between the departure of Oswald Boateng and the arrival of Ricardo Tisci — is on his way to achieving his goal.

Ami has struck a chord with both editors and buyers, who have taken to the label’s winning formula of stylish but affordable wardrobe essentials — from jeans to shoes to tuxedo jackets — and core concept of a brand for friends, communicated through casual presentations staged in gardens or apartments, where models hang out with drink and cigarette in hand.

“Regarding the pricing formula, we did things in a very organic and simple way,” says Mattiussi. We asked ourselves, ‘How much should a t-shirt cost?’ and then we analysed the production and looked for the manufacturers who were able to make the products we wanted.”

The designer is not afraid to admit that the factories making his accessible, but high quality clothes are situated in low-cost countries like Portugal and Romania. “When you’re a designer, you always want the best the best fabrics, the best details. Our challenge was to have that, but at reasonable prices.” For Mattiussi, that meant meeting with lots of different manufacturers and spending hours on the phone negotiating prices. No wonder the designer is hesitant to reveal more about how he manages production, a key component of Ami’s success.

Influential retailer Barneys New York picked up Ami's first collection. "Mark Lee coming to the shows and wanting the collection on the spot meant so much to me," admits Mattiussi, referring to the venerable department store's chief executive. And today, Mattiussi's young brand, now in its fourth season, is stocked at some of the world's most prestigious stores — including Bergdorf Goodman, Opening Ceremony and Corso Como — and operates its own store in the 4th arrondissement of Paris. "Sales are up by at least 50 percent each season," says Mattiussi.

But this success didn’t just fall into his lap.

Mattiussi first launched his own fashion venture back in 2002, starting a small label, also called Ami, making shirts and t-shirts that were sold at Lane Crawford in Hong Kong and Intermix in New York City. The business was ultimately too much for the young designer to manage, however, and was closed.

His second attempt was very different, thanks to one man: Marc Jacobs CEO Bertrand Stalla Bourdillon, who, more than anyone, first helped put Ami on the path to success.

“He made me realise that I couldn’t do it all alone, that I needed a team — a professional and solid team — and that I needed money.” So, instead of bootstrapping the company, Mattiussi sought out investors. “I went to see banks, private investors; I went looking for ‘smart’ money, people who would want to be a part of the brand, not just patrons who would give me donations. I wanted participation that would be financial and human.”

Bourdillon also introduced Mattiussi to Daniel Piette, president of LVMH’s private equity arm, L Capital. Alexandre spent months working on business plans with the two seasoned executives, then “one of my friends introduced me to a young investor, very creative,” who would become Mattiussi’s press-shy business partner.

Armed with financial resources "between 200,000 and 400,000 euros," as well as advice from Bourdillon and Piette, Mattiussi was able to take up a showroom and office space in the heart of Paris, hire KCD, one of fashion's most influential public relations agencies, and cover his initial production costs, moves that undoubtedly helped set the young company up for success.

“For next summer we have also worked on a full range of sneakers; we will also introduce sunglasses. As for bigger projects, we are still in the brainstorming phase of Ami (petit), which will be a line for boys.” In May, the brand is set to launch an exclusive capsule collection on e-tailer Mr Porter, followed by a full e-commerce launch in September.

As for the speculation behind a women’s line rumoured to be called “Ami(e), Mattiussi is in no rush: “Everyone keeps asking me for one, but I don’t think I will get on that just yet. It’s all about taking things slowly.”