From Chanel No. 5 to Dior's Addict, when a fashion house looks to fragrances and cosmetics for business, it's testimony to their place in luxury's hall of fame. While fashion and accessories come with heftier price tags, lip tints and fragrances dripping with a brand's essence present themselves as more "affordable" yet equally coveted options.

Many fashion houses have jumped on the bandwagon - Tom Ford, Burberry, Dolce & Gabbana, Gucci and Christian Louboutin. Lanvin, 3.1 Phillip Lim and Proenza Schouler have also opted to work with beauty brands on one-off capsule collections instead of launching full collections.

The results have been phenomenal. Tom Ford's sensual scents, high-pigmented eye colour palette and lip colours have been flying off the shelves since their 2007 launch. Tom Ford Beauty is expected to turn over more than US$275 million in retail sales this fiscal year, according to reports.

"I've cared about cosmetics and make-up since I was a kid, and at Gucci, I'd spend days working with a make-up artist to perfect the show look," says Ford, a former Gucci creative director who partners with industry giant Estée Lauder for his namesake beauty line. "I never had a desire to wear the clothes, but make-up? That I'm serious about."

Many have been tempted by the riches. Burberry expects 25 per cent growth in its beauty wholesale revenue in 2015. Gucci and Dolce & Gabbana's long-standing fragrance line with Procter & Gamble Prestige has convinced them to strengthen their collaboration. Dolce & Gabbana launched in Hong Kong in November last year and will soon release its Sicily-inspired luxury skincare line. Gucci Beauty launched this month in Hong Kong and is available at exclusive counters around town.

Entry-level price points have helped brands expand their client base. "Of course, cosmetics are more accessible," Ford says. "Our customer is the Tom Ford woman and anyone who aspires to be [one] if they can afford it."

Phillip Lim agrees. "It reaches out to new customers," he says. A capsule nail varnish collection by the Council of Fashion Designers of America honouree, which was launched in collaboration with NARS this summer, has sold out. Compared to his signature boxy Pashli satchel, which fetches more than HK$10,000, the nail varnish, retailing at HK$180 a pop, is much more affordable.

Fashion brands tread a fine line with their brand image when they expand into beauty and cosmetics. Control and moderation through exclusive distribution channels and price points are tactics used to maintain the luxury image.

"Beauty is approached the same way we do with fashion - we make luxury products," Ford says about his beauty collection and luxury perfumes, some of which cost more than HK$4,000.

Christian Louboutin Beauté's new nail varnish collection takes high-end beauty a step further. Instead of being sold on the beauty floor, the nail polish, retailing at HK$450, is available only in Louboutin stores, at the online shop and select retailers such as Lane Crawford and Bergdorf Goodman. "Beauty has always been an entry point for luxury brands," says Catherine Roggero, general manager of Christian Louboutin Beauté.

"However, this has often been translated as a diluted vision of the creator in order to be affordable luxury. We strive not to compromise the design aesthetic, the formula and the experience in our products."

While the fashion peg attracts sales in the launch period, quality products are what retain fans in the long run. Designers often take a hands-on approach to achieve a legitimate product selection in beauty and cosmetics.

Gucci took four years to develop a beauty line. Creative director Frida Giannini tested all the products herself and developed details with P&G's team such as the elegant mechanism that closes a face-powder box and a mascara formula designed to last the whole day. For the collection, Giannini worked closely with British make-up artist Pat McGrath, who has developed cosmetics for Giorgio Armani and Yves Saint Laurent and is a regular inspiration during fashion weeks.

Dolce & Gabbana duo Stefano Gabbana and Domenico Dolce work with ingredients native to the brand's Sicilian roots such as olives.

"The collection was created for a generation of confident and cosmopolitan women," Dolce says. "We have been working on the line for years. Every little detail contains a little bit of our philosophy."

As fashion brands search for their partners, conglomerates such as Estée Lauder, L'Oreal and P&G appear the most eligible for product development, distribution network and marketing. The long-term relationship with the industry giants in the fragrance business is another important rationale.

Gucci and Dolce & Gabbana worked with P&G on their fragrances prior to the cosmetics and skincare launch. Estée Lauder operates beauty and skincare for Tom Ford, Marni and Tory Burch, while L'Oreal's portfolio includes Yves Saint Laurent, Giorgio Armani and Maison Martin Margiela.

"One of the reasons I wanted to work with Estée Lauder was because I wanted a full collection of make-up and skin care," Ford says. "I'm very excited to have the world's expert in beauty and fragrance as my partner."

Others chose to work with boutique beauty firms or take it in-house. Examples include Christian Louboutin's partnership with Batallure Beauty and Hermès' in-house perfumer Jean-Claude Ellena. Last year, Burberry ended its fragrance licence agreement with Inter Parfums to take the business in-house by starting a Burberry Beauty division.

Louboutin's Roggero says a boutique approach allows a designer's vision to shine through. "It's a privilege to have Christian [Louboutin] engaged in all aspects of the business," Roggero says. "It's refreshing to work with a designer who has no preconceived notions. His approach has been very organic and natural, and he follows his own instincts."

Beauty products that project fashion designers' philosophy and are developed with a well-rounded formula benefit the fashion brands and their beauty counterparts.

"A successful collaboration helps create a win-win situation," says Diana Ho, Shu Uemura Hong Kong's brand manager. The cosmetics and skincare brand, which is owned by L'Oréal, has worked with renowned designers Karl Lagerfeld, Tsumori Chisato and Viktor & Rolf since 2004. Shu Uemura is working with Lagerfeld again this coming festive season for a collection inspired by his cat Choupette. Ho says there is greater demand for crossover products during busy periods.

"Brand collaboration strategies help us to navigate through a less familiar market by joining forces with other market leaders," Ho adds.

"If it feels right, then nothing is too much," Lim says. "So much of growing the brand to where we are today comes from following our intuition, and I don't think I'm going to stop that now."

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