Define what you are observing
In this guide, longevity means how long you perceive a fragrance, projection means its presence at a distance at a particular moment, and sillage means the trail you or another person notices with movement. These are three observation questions rather than interchangeable scores. Write down which one matters for your intended use before comparing samples. You may want a restrained surrounding presence while hoping to notice the fragrance again later. Those wishes deserve separate observations instead of being compressed into a single request for a strong perfume.
A pyramid does not provide the result
IFF's professional article about perfume creation presents top, heart and base notes as a way to explain development. That organisation does not establish a particular bottle's longevity in your circumstances. A base note is not a number of hours. Vanilla or musk in a description does not supply a projection distance. Similarly, an Eau de Parfum label cannot rank two distinct compositions for duration or perceived strength on its own. Keep the product vocabulary as information about the presentation rather than turning it into a performance calculation.
One notebook, three lines
Create a sampling record for the exact version. Note the date, location, chosen application surface and your application approach while following the product's instructions. Then separate three lines: perception over time, presence around you and impressions during movement. Record observations at moments you choose beforehand. If the setting changes, say so. The aim is to make a personal experience understandable, not construct a laboratory protocol or a value that applies to every wearer. Leave space for the information you could not reliably observe during that session.
Keep a comparison understandable
For a personal comparison, keep your sampling approach reasonably similar and avoid layering the fragrances on the same surface. Allow yourself to write uncertain when an observation is difficult. If another person willingly takes part, retain their own words and the circumstances. A single comment should not become an objective measurement. You will have a more useful account than a global strength score: it will explain what was noticed, when and under which conditions. That is enough to support a thoughtful next sampling choice without claiming universal performance.
Ask better than is it powerful
Replace the broad question with your situation: do you mainly want to notice it at close range, during movement or at several points in your routine? Return to samples and exact product versions with that question in mind. A review becomes more informative when it names the setting and separates preference from observation. Soft, fresh, clean and intense can describe several different things, so ask what the person means. Two comments sharing an adjective do not automatically provide a comparable account of how long the perfumes remained perceptible.
What the hub contributes
Olfatlas helps you select compositions to explore by comparing published notes and their sources. The Finder does not turn those notes into predicted performance. Use it to build a small shortlist, then return to this notebook for sampling. If a brand page makes a performance claim, preserve its attribution and scope instead of treating it as our own measurement. We assign no hours, distances or compliment promises to these fragrances. The purpose is a decision supported by clearer observations, exact versions and visible limits to what the record can establish.
Sources and references
These links provide the references used for this article. A reference does not verify every fragrance listed elsewhere in the catalogue.