During the construction of the Park Hyatt Vendôme in Paris, a newspaper article about an obscure perfumer caught the eye of the hotel's gouvernante générale, Marie-France Rey. It reported that Blaise Mautin, a 37-year-old Frenchman, had recently created a scent for a rival establishment. What really got Rey's attention was this: The fragrance was not a cologne for guests nor was it a spritz to be sold at the gift shop; it was a scent to be worn by the hotel itself.

In her mission to make Park Hyatt Vendôme one of, if not the most sumptuous hotel in the world, Rey-like so many others in the business of top-end goods and services-had obsessively accounted for what she thought was every possible sensory experience. Architects were hired to lavish their attention on the sense of sight by calibrating lines and gauging colors. Designers were enlisted to delight the sense of touch with satiny tumbled stones and polished woods. Engineers came in to court hearing with soundproof windows and expensive audio systems; chefs obsessed over vegetables, meats, and spices. There were even musicians working to produce a unique sound for the place. But amid all this spare-no-expense attention to detail, there was a void in the impending Park Hyatt Vendôme experience, which Rey was now determined to correct. She immediately tracked down Mautin and asked him to turn the hotel's atmosphere and interior into a signature fragrance, one that would become as essential to the hotel's identity as the interior courtyards and the modern aesthetic designed by Ed Tuttle.

The power of scent to create memory made Mautin a perfumer. Growing up in the 16th Arrondissement, he often helped out at his aunt's shop-the legendary Paris toy store Au Nain Bleu, just down the street from Hermès on the Rue Faubourg Saint-Honoré. "I was twenty-three and working as a salesman at the store," he recalls. "One day, from a large limousine I saw descend, as if from a long-ago era, an exquisite little girl followed by her elegant grandfather. They entered the shop and stopped before a display of suitcases in seven lovely colors. The grandfather asked, 'Which do you like?' She said, 'I like them all!' So he bought all seven. They were two thousand dollars apiece. Then he added stuffed bears, dolls, toys. I saw the look of utter joy on her face and I thought, What she needs to remember this experience forever is the scent of an Au Nain Bleu fragrance. When she is old she'll smell it again and instantly be brought back to this moment." For the little girl, it was a perfect Christmas and the best birthday rolled into one. For Mautin, it was an epiphany: "I understood right then," he says, "that with time, only scent remains."

Mautin began his creative process for transforming the Park Hyatt Vendôme environment into a fragrance by viewing the two model rooms. "They were extremely sexy," he says, "a mix of modern and classic. I also noticed a slightly Japanese feel in the clean lines and the quietude. From the first visit I had a very strong sense of the place."

For months he and the hotel team met regularly. The group discussed design, quality, and the philosophy of pleasure. Mautin absorbed it all. He knew they were taking a risk on him, a young artisan with a perfume lab in his apartment. The team asked questions and he answered them. "They let me create," Mautin says. "'Proposez-nous!' they told me."

And so he did. He presented several possible directions. (To the team's delight, Mautin brought in his first essai in bottles on which he had pasted his business card.) One was built on woody, minty patchouli, in homage to the hotel's rich mahogany details. Another was a vetiver, a green musky incense with a bit more tang. They chose the patchouli. "C'est plus nous," they said ("It's more us"). Mautin agreed.

Over a period of several months and multiple meetings, the perfumer continued to develop the olfactory logo. To soften the patchouli ("It can be a bit stiff," Mautin admits), he used an extract of sweet Brazilian oranges from the famed French Scentaromatique in Grasse. He put in a natural sandalwood as well as a synthetic molecule trade named sandalor. (Contrary to common notions, synthetics are among the most beautiful and pure perfume materials on the market. The key to Chanel No. 5, for example, is one called aldehyde.) Mautin also added ethyl vanillin and absolue de vanille (the first is synthetic and the second natural) to impart a subtle powdery amber element and softness, along with a leathery-scented base from Russia that he compares to the comforting scent of burning wood. The finished formula, which only Mautin knows, contains more than 18 materials.

It is a testament to Mautin's artistry that his Park Hyatt Vendôme scent meshes flawlessly with every aspect of the hotel: the field of white orchids at reception, the smooth flowing lines of Ed Tuttle's spaces, the finely textured surfaces, the luxe Thai silks. The fragrance's brilliance lies in its subtlety; the substance isn't instantly identifiable-it's not a wood, not a flower. Not that the scent is beyond description: It smells of fresh cement poured over a raw oak plank, plus fresh, ever-so-slightly cinnamony pastry dough, with the olfactory texture of thick, rich tan silk. An unlikely mix to be sure, but it works. The point, however, is that one doesn't need to describe it; you simply experience it. The aroma enters you, and if you somehow ever get even a hint of it, maybe on a street in Los Angeles or a hillside in São Paulo, you'll instantly be transported back to the Park Hyatt Vendôme in Paris.

This hotel, it turns out, is but one of a group that has recently made efforts to address the long-neglected fifth sense. The perhaps best known example is found on the other side of the Place Vendôme from the Hyatt. There, the Hôtel Costes has introduced an impressive luxury-scent experience with three different scents-the original is red, dark and thickly aromatic and has become rather essential to the hotel's character. It is also a cult of its own: The hotel sells crate upon crate of the scented candles, at 45 euros each. A rich, deep, tropical aroma of full-throated flowers and woods was recently created and placed in every Mandarin Oriental spa on the orders of Ingo Schweder, who directs the chain's spas worldwide. "Smell is underleveraged," Schweder says, "and because of the overload from sight and sound, people are more receptive and more sensitive to communication via scent." Martin Lindstrom, a preeminent scent-branding marketer, agrees: "Sensory branding has shown to be the secret key in helping companies build an emotional attachment with customers by systematically targeting all the senses."

Considering how extraordinarily important perfume is to the big fashion houses, hotels were bound to wake up sooner or later. Mautin's Park Hyatt scent has now been adopted by the Park Hyatts in Madrid, Moscow, Zurich, Dubai, and Baku. The demand from hotel guests became so overwhelming that beginning this year the Park Hyatt Vendôme will, with some reluctance, start making its scent logo available to the public.

What if guests don't like the fragrance? people often ask. To this question, general managers who have scent decors respond, "What if they don't like the color scheme, the music, or the menu?"
Park Hyatt Vendôme, 5 Rue de la Paix, Paris; 33-1/58-71-12-34.

The proprietary fragrance is the latest luxury amenity offered by top hotels. Here, Chandler Burr's map to the perfumed lobbies of the world.

THE OBEROI GRAND
Where Calcutta
Creator Anonymous, found locally and adopted exclusively for the hotel
Scent A revitalizing, refreshing wash of eucalyptus, pine, lemongrass, and oils from Bangalore. Guests will sense it in the lobby and in the guest rooms at turndown.
Etc. It's available at the hotel shop and spa as an oil and incense stick. 91-33/2249-2323

HOTEL METROPOLE
Where Monte Carlo
Creator Designed by Maude Lesur and crafted under her direction by perfumer Pamela Prache of Tradition & Parfum
Scent Subtle and stunning due to the fact that there is not a fruit, flower, or wood you can identify. It is, as literally as possible, the purest abstract scent of luxury: rich, smooth, silken, striking without being loud, crystal clear without raising its voice. It greets guests at reception and every entrance.
Etc. It comes as a candle-wrapped in a pochette designed by Jacques Garcia-obtainable from the concierge. 377/9315-1515

CONRAD
Where Tokyo
Creator Perfumer Tatsushi Horita of Shiseido
Scent Actually two: Très Vert, which perfumes the guest-bathroom amenities, possesses thoroughly strange, contemporary Japanese urban smells, morphing from a soothing green tea to a new spaceship. Très Noir, scenting the rooms facing the skyscrapers of Shinbashi and Ginza, smells of nighttime and Tokyo's glass towers. It is an essential ingredient in all the guest-room amenities.
Etc. Scented candles can be requested by hotel clients only. Bath products may be purchased in the Conrad's shop on the 28th floor; a full package-shampoo, conditioner, body lotion, bath gel, and soap-costs $39. 81-3/6388-8000

THE CARLYLE
Where New York
Creator Perfumer Lyn Harris of Miller Harris, London
Scent A surprisingly dark, smoky fragrance of deep wood and green trees. Harris says she constructed it while looking out at Central Park, but the scent suggests a wild, primitive woodland of a Byronesque imagination. Clearly present in the lobby, restaurant, and rooms, which are all scented with candles.
Etc. The candles can be bought at the concierge desk. 212-744-1600; www.thecarlyle.com

PARK HYATT MILAN
Where Milan
Creator Perfumer Laura Tonatto
Scent The lightest veil of amber is blended into a combination of aromas: a touch of delicious paper-thin caramel toffee on an Italian pastry, mixed with fresh bread baked in a wood-fired oven that has just been dusted with flour, the crust so light and transparent it looks like a crisp gauze ribbon on the dress of a beautiful woman. Guests will sense it in every inch of the hotel.
Etc. The scent is available for purchase through the concierge. 39-02/8821-1234

THE DORCHESTER
Where London
Creator Lyn Harris
Scent A lovely fruity fig, clean with a bit of green organic. It is dispersed in the lobby and hallways via the ventilation system.
Etc. The scent is available in a candle from the hotel boutique. 44-207/629-8888

LANGHAM HOTEL
Where Hong Kong
Creator Belmay
Scent Its name is Ginger Flower, and this delicate, ethereal scent lives up to the moniker-soothing yet very urban, as if the towers of glass and steel have been turned into a gigantic spa. It will follow guests throughout the hotel.
Etc. The hotel's boutique sells it as a home spray. 85-2/2375-1133

MANDARIN ORIENTAL
Where 15 Mandarin Oriental spas worldwide
Creator E'Spa
Scent A rich scent of tropical Asian flowers, woods, and greens composed of 25 roots and herbs. It is an essential ingredient in the massage oil and spa products by E'Spa.
Etc. Products can be ordered directly through the spa. 212-805-8880

HOTEL COSTES
Where Paris
Creator Perfumer Olivia Giacobetti
Scent The hotel has created three custom scents, but the original and signature fragrance is a warm mix of musk, coriander, laurel, and white pepper. The scent permeates every nook of the property.
Etc. Scented bath products, room sprays, and candles are sold at the concierge desk. 33-1/42-44-50-02