Why Your Fragrance Trails Behind You

When it comes to perfume, I've always erred on the side of discretion. I've spritzed rather than splashed. I've made a point to wear only fragrances I perceive as quiet-­perhaps fearing that if anyone around me should catch too potent a whiff, they might form an unfavorable opinion about me. I haven't truly loved-in a desperate, nostril-flaring, want to suck it all in way-very many perfumes. There was a scent given to me by a boyfriend in college, its (and his) name long forgotten, that smelled exactly like mimosa flowers: Every time I applied it, I could see those fuchsia pom-poms-their resemblance to Dr. ­Seuss illustrations always a source of delight-blooming in the yard of my midwestern childhood home. In my twenties, I had a fling with lily-of-the-valley Dior Diorissimo, so evocative of that moment when the first hyacinth bouquets appear in New York delis in the dead of winter, like a promise of spring. But my current favorite is a scent by botanical Strange Invisible Perfumes called Dimanche ("Sunday," en français), and when I inhale it I practically levitate with pleasure. It's not just that its notes-a mélange of iris, rose, honey, and something suggestive of sun-dried hay-transport me back to my grandparents' Kansas farm, of which I have little conscious memory, but because I feel that at last I've found a fragrance that smells, ineffably, like me. For the first time in my life, I want everyone else to smell what I'm wearing. Not in an overpowering, please-God-let-her-get-off-the-elevator way, but in a subtly insinuating, ghostly way. I want it to be the scent that people remember me by. Not only when I'm gone gone, but when I've simply left the room for a few minutes.

Why You Catch a Scent After the Wearer's Passed By

The fragrance trail-technically, its sillage-is perhaps one of the most misunderstood aspects of perfumery. Many people associate its presence with the type of walloping, intrusive fragrances that can turn a crowded cinema into a gas chamber. But it's actually something entirely different, and-in intention, at least-thoroughly elegant. The word sillage is French for "wake," like that left by a boat as it moves through water. I like to picture it as the vapor trail of an airplane as it crosses the sky: It's something that hangs in the air intangibly, and just as you begin to get a fix on it, it's gone.

"Sillage is the projection, or the bloom of a fragrance," says Sophie Labbé, the noted nose behind such scents as Calvin Klein Beauty, Bulgari Jasmin Noir, and Very Irrésistible Givenchy. "It's different from the intensity or power of a scent; sillage is more of an aura. You feel it, but you aren't overwhelmed by it."

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In other words, it isn't that first gotcha blast that slaps you in the face at the perfume counter-it's the eau's afterglow, the tantalizing whiff of something wonderful that you catch after someone passes you on the street. Sometimes referred to as "lift," sillage is how far a scent travels away from the wearer, not how long it lasts on the skin. Because of its lingering quality, it's also fundamental to the memory-making magic of a juice: The reason why you think of your great-aunt Margaret every time you smell Chanel No. 5 is probably as much because of the times you detected it in the air when she wasn't there as when she was.

Which Notes Evaporate Fast and Which Stick Around

Fragrances don't need to contain anything particularly tenacious or stealthy, such as patchouli, in order to trail; the character of the scent can be light or dark, floral, fruity, woody, sweet, or spicy. It's possible for projection to come from the dry-down, which is where you typically find heavy base notes such as musk, vanilla, or amber, but it can just as easily emanate from the top or heart notes. Sillage is the product of evaporation, aided and tweaked by alchemical wizardry. Although some notes are more naturally diffusive than others-the difference between a quick-to-evaporate grapefruit note and the hang-about scent of musk is like the difference between a note hit on a piano key and one held, say, by an oboe-talented perfumers can manipulate even the most transient whiffs so that they stick around longer, just as they can tamp down those that are more persistent.

"It's a complex chemistry involving a lot of different molecules and how they interact with one another," explains Pascal Gaurin, a senior perfumer at New York scent-industry giant International Flavors & Fragrances, whose creations include Harajuku Lovers Love and Michael Kors Very Hollywood. "For example, water boils at 100 degrees Celsius, but if you add another product to it you can lower that threshold or make it higher. If you have an ingredient that evaporates very quickly-like lemon oil or bergamot, which go rapidly into the air so people perceive them right away-you can make it last longer by adding something that has a slower rate of evaporation."

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What's Your Sillage?

There are different levels of sillage-that's why you can smell some people coming before they enter a room but have to lean in for a good wrist-sniff to detect a perfume on others. Some scents have what fragrance bloggers often refer to as "monster sillage"-which I assume is what I experienced when I sprayed Clive Christian C for Women in my apartment, and even an hour later the smell was so strong I needed to open the doors and windows to let it out-and some are so low-key they're almost trailless. The desirability of one or the other depends largely upon the personality of the wearer. What would you prefer as your personal accompaniment: a marching band or a violin trio? Because bold sillage has a sort of room-filling 3-D effect, essentially extending the space you take up in the world, it requires a certain level of confidence-maybe even self-importance-to pull off. It makes sense that iconic '80s fragrances such as Dior Poison and YSL Opium were not just strong perfumes at first blast, they were also major trailblazers: That was no era for the meek.

What the French call parfums de peau, or skin-scents-perfumes in which diffusive ingredients are kept at a minimum so that they stay close to the body-are at the other extreme. Until I found Dimanche, this was my ideal: a perfume only I, and the people I was closest to, could discern. Nick Steward, head of product development for L'Artisan Parfumeur, believes that these types of fragrances embody a different, very modern type of indulgence for many perfume lovers. "For a certain type of customer, it feels more luxurious not to broadcast," he says. "They want something more delicate and personal." It's like choosing pretty lingerie instead of heaped-on bling.

It's also a question of public versus private notions of sexiness: "Some might find a fragrance with less sillage to be more seductive," Labbé says. "It's more intimate, so it makes men come in closer." Or, she points out, it might have nothing at all to do with being social. "A quiet sillage is a fragrance for yourself, for your well-being. It's not to make people approach; it's just for you." Personally, I can understand that quite well: In New York City, where every block boasts a new malodorous surprise, there's been many a time when I've sought solace in scent. If I'm sitting on a subway car that smells like sauerkraut feet, it's nice to be able to put my wrist to my nose and inhale a heavenly whiff of a garden in the south of France. At the same time, I can also see why a monster sillage might come in handy in the exact same situation: It's a way to push back against the encroaching world, not just retreat from it.

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The Ideal Sillage

For most perfumers, the ideal sillage falls in the middle range: not too strong, not too weak. "You want perfume to be diffusive enough to be its own advertisement," says L'Artisan Parfumeur nose Bertrand Duchaufour, who points out that "virtually all" of the top-selling scents in America and Europe have a readily discernible trail. "When someone is wearing it, they want someone near them to ask, what do you wear? The trail of a fragrance is its first criteria of success. Just think of Thierry Mugler's Angel, for instance-it became so popular because it was powerful enough that everybody noticed it."

Gaurin agrees. "I have never," he says, "been in the lab to make sure a fragrance does not diffuse."

But at the same time, unless you're feeling particularly '80s throwbacky, you don't want your sillage to be an entity. It should be more like the soft brush of a cat's tail as it weaves past someone's ankles than like a knockdown, slobbery greeting from an over-friendly dog. It is somewhat possible to calibrate the throw of your scent: Perfume diffuses more (and lasts longer) when applied to well-­moisturized skin than dry skin (think about how much more aware you are of fra­grances in humid climates-same idea), and dabs of an eau de parfum, which is more concentrated, tend to project less than spritzes of an eau de toilette. It's also easy to select a perfume according to environment-you might want a more discreet sillage in the office, for example, than you would at a party. The million-dollar question, since most of us stop being able to smell our own perfume once our noses become accustomed to it, is: How can we tell whether or not the trail we're leaving behind is a good one?

"There are a lot of people who are wearing very powerful fragrances and don't even know it," Gaurin says. "It's difficult to determine the sillage of your own perfume. So it's important to watch people's reactions when you wear it." If people are wincing and backing away, it's probably a bit much, but "you know you have something very good when you get into a car and the driver compliments you on what you're wearing." Labbé suggests another strategy: "Spray the fragrance in a room­-not on your skin-and then come back 10 minutes later. If you can still perceive it, then that's the sillage."

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I've tried an even more scientific approach: walking back and forth in front of my coworkers, flapping my arms, asking, "Can you smell me?" It turns out that my beloved Dimanche lands firmly in the low-sillage camp-not surprising, considering it's an all-natural eau, which tends to be more fleeting than those with chemical fixatives. Alexandra Balahoutis, the founder of Strange Invisible (a perfumery, incidentally, named after one of the greatest sillage events in history: the moment in Shakespeare's Antony and Cleopatra when the Roman triumvir first catches a whiff of "a strange, invisible perfume" emanating from the scented sails on the Queen of Egypt's boat), tells me that she, personally, prefers low-radius scents: "I like fragrances to lift off the person, but I don't think they should linger too long after they're gone," she says. "I think it's really nice when you're wearing a perfume, and you just smell beautiful and people associate it with you. It's definitely there, they definitely notice, but it's subtle and elusive and a bit mysterious."

I like the sound of that. I don't think I'd be comfortable with a high-octane sillage, anyway. I don't need my perfume to scream "I'm here!" What I want is for it to whisper "I was here." I want it to flutter behind me like a veil and then vanish, lingering more indelibly in memory.

There's a famous saying: "A woman who doesn't wear perfume has no future." That's debatable. But in a sense, at least, she definitely doesn't have a past.

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