It’s frustrating to discover a fragrance, get all worked up about it, put it on the skin, and have it disappear in 20 minutes. Perfumers describe this phenomenon as caused by a lack of “fixation,” the idea being that certain ingredients— “fixatives” --“fix” the perfume and get it to last longer. Typically, resins, woods, or persistent molecules, most fixatives have high boiling points and evaporate slowly. The accepted wisdom is that fixatives combine with the rest of the perfume and slow its volatilization.

While this is partially true, the fixatives often persist, but nothing else. Sometimes fixatives fail to restrain other, more volatile, ingredients, causing the perfume to shift from whatever prevails in the beginning (top and middle notes), to the aroma of the fixatives alone. In the 1950s, my mother often came home late from parties, wreaking of natural musk, the other aromas in her Vol de Nuit, long gone.  

There is certainly no inherent problem with a perfume shifting character from the beginning to the end, provided it is pleasant during its entire duration. However, it seems to me that if a perfume promises something, say rose or tuberose, it should smell that way through most of its duration. On the other hand, a perfume with a fanciful but ultimately meaningless name that’s more about a fantasy—“Opium,” say--we may be delighted to witness it go through its changes.

So, where does this leave Black Iris? I might be in a pinch. I’m promising iris and if the stuff doesn’t smell like iris the whole time, then it’s no longer iris. But what if the public doesn’t know what iris, much less black iris, smells like?

Soon, more about the difference between an iris and a black iris.

For some perfumes, the greatest challenge is getting them to last. Natural floral aromas, especially, evaporate quickly—no more than an hour or two on the skin—and need to last longer to be viable.

It has long been the supposition of perfumers, master and otherwise, that by combining a rapidly evaporating substance with a slowly evaporating one that the evaporation rate of the quickly evaporating compound is slowed down. With this in mind, heavy, thick and viscous substances are added to perfumes. Such substances as benzoin, musks, oppoponax, sandalwood and a myriad of others retard the evaporation of top and middle notes. Overdoing it—adding too much of a viscous substance—will flatten the perfume and create too much restraint.

Another approach is to recreate the perfume using heavier notes such that there’s a backup perfume profile to take over when the first evaporates. In other words, say you add oxyoctaline formate. Because this compound is persistent, it will remain in the dry down and give the impression that the perfume is long-lasting, when in reality the first part of the perfume—that part from which it finds its identity—will have evaporated.

When I was investigating other iris perfumes when I was working on Black Iris, which turned into Green Iris, I found a number of perfumes that started out with a strong iris accord, but ended, hours later, smelling like something else entirely.

Perhaps the most famous fixative of all, is ambergris, confusingly referred to as “amber.” A small amount of tincture added to a perfume gives a life-likeness and vibrancy that otherwise would be missing. I’ve noticed how after a few weeks from blending it seemed to make perfumes blossom. Few perfumers use ambergris anymore which is strange since, while expensive, it is a lot cheaper than other things we still use. Substitutes such as ambroxan, ambrinol, ambercore, and andrane are typically used to provide this essential “amber” note. These are long-lasting compounds and, like ambergris, help fix the perfume.

While I want to remain true to iris and replicate its lovely rooty, earthy, and floral aroma, I haven’t just promised iris, I’ve promised black iris. Since few people know what iris roots smell like and far fewer, if any, know the aroma of black iris, I’m allowed a bit of fantasy.

Instead of getting the black and the iris to function together, I’ve decided to get them to present at different times during the dry-down. In other words, the perfume will start out like iris and get darker and blacker in tone as the iris fades and my faux natural musk moves to the forefront. The iris will go from purple to black. It worked as predicted, without the musk fixating the rest of the fragrance. The musk does persist, undetectable during the first whiffs of the iris, gradually revealing itself as time goes on. While the approach worked, I still wanted the iris aspects to last longer.

I may have made a helpful discovery. Older perfume formulas often call for concretes. A concrete is an extract, usually a solid, and an interim product when making an absolute. Typically, concretes contain large amounts of waxes and other high-boiling-point materials, so the obvious thing was to track down some concrete made out of iris. This was not easy as few people use concretes and they’re rarely sold. After my tiny sample of iris concrete arrived in the mail, I added some to the formula and it worked like a charm. The perfume smells great, projects reasonably well, and, most of all, lasts for hours on the skin. There is only one problem: iris concrete is expensive. Have I made the perfume exorbitant? Whether people will pay for this loveliness, I don’t know.