Short answer
To test a perfume's longevity and sillage, wear-test a near-final version under controlled conditions: apply a measured dose to the same skin sites on several people, check at fixed times how strong it is at the skin and at set distances, and compare it in the same session with a reference perfume whose performance you know. Record the dose, conditions and each person's ratings on a consistent scale. Results are subjective and vary between people and climates, so treat them as a comparison against your reference, not as a number of hours to print on a box.
Three different properties
- Longevity — how long the perfume remains detectable on the skin.
- Projection — how far from the skin it can be smelled at a given moment.
- Sillage — the trail it leaves in the air as the wearer moves; in practice often used interchangeably with projection.
They do not always move together. A perfume can project strongly for an hour and then sit quietly on the skin all day, or stay close to the skin throughout and last a long time. Decide which matters for the product before testing.
When to test
Performance testing comes late in development, on a version that is close to final and has rested properly; a freshly mixed trial can perform differently a few weeks later (see perfume maceration and aging). Earlier, comparing trials on blotters at fixed time points is enough — that is the routine in how to evaluate a perfume formula.
A wear-test protocol
Prepare
- The test perfume and a reference — an existing perfume, ideally your own previous version, whose performance you know.
- The same bottle type and sprayer for both, or dose by weight.
- Four to eight wearers if you can; one person is not a test.
- A sheet for each wearer with times, scales and space for notes.
Apply
- Use a fixed dose: a set number of sprays from a sprayer you have weighed (spray into a tared vial ten times and divide), or a weighed amount from a pipette.
- Apply to the same sites every time — for example the inner forearms, test on one arm and reference on the other, swapped between wearers so neither always gets the same side.
- Record the time, temperature, and anything on the skin (moisturizer, recent shower).
Check
| Time | At the skin (0–5) | At arm's length (0–5) | Notes |
|---|---|---|---|
| 15 minutes | Rate | Rate | Character |
| 1 hour | Rate | Rate | Character |
| 3 hours | Rate | Rate | Character |
| 6 hours | Rate | Rate | Character |
| Next morning | Rate | — | What remains |
Use one intensity scale throughout — for example 0 none, 1 barely, 2 weak, 3 clear, 4 strong, 5 very strong. "At arm's length" is a crude but repeatable projection check; a second person smelling from a set distance is better than the wearer judging their own.
Reading the results
- Compare test against reference wearer by wearer; differences between people are usually larger than differences between perfumes.
- Look at where the curves diverge: a weaker opening, a faster middle, a longer tail.
- Expect variation with skin, climate and season. Hot, humid conditions usually increase projection and shorten longevity.
- Report results as "lasted longer than the reference for six of eight wearers", not as a precise number of hours.
Changing performance
Results point to what to change. A weak tail suggests the base or fixation; a short burst suggests the top is too volatile for the brief; low projection may call for more diffusive materials. Perfume fixatives explained covers what fixation can and cannot do, and concentration is the other lever — see how to calculate perfume concentration. Change one thing per version and repeat the test against the same reference. The development process this sits within is described in the perfume formulation guide.
Claims about performance
If you intend to make a claim such as "lasts all day" or a number of hours, the test behind it needs to be robust enough to support it, and in some markets advertising claims must be substantiated. A small internal wear test is a development tool; it is not, by itself, evidence for a marketing claim. Claims that suggest an effect on the body are a separate and more serious matter, discussed in when a perfume claim makes it a drug.
Frequently asked questions
Can I test longevity on blotters?
Blotters show how long the materials last on paper, which is useful for comparing trials. Skin is warmer, absorbs some materials and has its own odor, so blotter results do not translate directly into hours on skin.
Why does the perfume last longer on some people?
Skin type, temperature, hair and products used all affect evaporation and perception. That variation is why a wear test needs several people.
Written and reviewed by the RUŌOD Lab team. This article is general education about perfume formulation and record-keeping; it is not legal, regulatory or safety advice, and the examples are illustrations, not validated commercial formulas. How we write and check these guides.