Which formulation componants tend to enhance longevity in a perfume ?

Gang,

This may be one of those standard newbie questions, but I was wondering which of the many chemicals in a perfumes formulation tend to lend longevity to a scent ?

Certainly longevity is a valued quality in a scent, and its likely that perfumers realize this as well. But I continue to read about fragrances, even those from high quality and respected lines which, by general consensus, simply dont last very long.

Is it that only certain primary fragrance components ( the ones selected mostly because they smell good) also bring with them the quality of persistence, or is it that certain other aromachemicals designed specifically for their ability to enhance longevity ( assuming that there are components designed and included primarily for this purpose) have a tendency to sabotage certain specific desired fragrance outcomes, and thus must be excluded from certain formulations ?

Probably not a question with a simple answer, but it does seem that some formulations (not limited to the all-natural ones) apparently find it necessary, for whatever reason, to limit or exclude components that enhance longevity.

Any ideas as to what those components might be, and why some formulations apparently dont or cant contain them ?

Thanks for you kind reply. I suspect that others here have also wondered about the chemical mechanics ( if you will ) of the drydown process.


Which means that certain fragrance components, as stand-alones, have intrinsic volatile lifetimes based on their inherent molecular weight alone.


OK, I think I follow you. After the alcohol has evaporated, the initial components are then left to interact among each other in a manner that can constantly change as each componant, and the varying compounds they interactively produce, gas off in ever-varying ratios based on the differing molecular weights of those compounds. Which could explain why people often report brief periods of less-than-consistant odor evolution as the hours progress.


Which would mean that they contribute to the longevity of lower-weight fragrance componants by combining with them to produce products of a higher molecular weight which off-gas at a rate slower than what those materials might do if left to stand alone.


I see. So one of the values of such fixatives is that they can be heaped into the formulation while apparently contributing relatively small fragrance changes of their own.


This is all well and good, but I'm still not sure if it answers my question. If fixatives are available which are orderless themselves, or can be added in high proportion to the intrinsic odors they do contribute, why do we still have perfumes of limited longevity from houses which would seem otherwise able to fork over the cash for such fixatives ?

While they may be orderless themselves, is it that the compounds they produce through their interactions with the intentionally fragrant components result in higher-weight compounds who's odors, while now more persistent, are at the same time incompatible with the fragrance profiles that the perfumer hopes to achieve ?

Perhaps it's that certain wanted odor profiles simply depend on final compounds of a necessarily low molecular weight in order to produce the smells the maker hopes to produce ? Beyond the initial top notes, I mean.

I guess I just have this sense that something beyond mere economics or simple dilution is at play when we come across fragrances with seemingly puzzling longevity issues.

Sorry, I suspect you can tell I was one of those kids who certain teachers hated when I was in school....

.

One often hears about just how long it can really take to perfect a good formulation, and all the effort, and all the unexpected twists and turns that are involved in that process. I suspect much of how that development actually proceeds is still mysterious to most of us. We hear about perfumes from otherwise respected noses which sometimes disappoint, and I find it hard to believe it's from a lack of skill.

So in some cases it may indeed be, as Otocione says, and as one often hears in knowledgeable reviews, simply a matter of the limited number of man-hours that are budgeted to the particular endeavor, rather than any inherent impossibilities in achieving certain outcomes.

I'm getting the sense that the explanation for shortcomings in longevity are more complex than an outfit simply being too cheap to throw in the needed fixatives. Perhaps I'm wrong, and fixatives are indeed one of the more expensive ingredients, and a reasonable place to skimp. But it comes to overall expense, I'm beginning to get the sense that the number of man-hours involved in reaching a desired end-point makes for the most expensive ingredient of all.