SESH · FRAGRANCE ACADEMY · INTERMEDIATE
Trace scent evolution, intensity and perceptual masking through a repeatable observation log.
Particles spread from higher to lower concentration. This is a qualitative model, not a perfume longevity timeline or a measured skin absorption rate.
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A pyramid is a teaching model
Top, heart and base are useful descriptors, not strictly separated chemical phases. Materials evaporate at different rates; strong impressions may mask softer ones; olfactory adaptation changes detection. A base-like impression can be present early, while an initially concealed facet can become clearer later. Your time log should follow observations, not force a diagram to be literal.
Three separate measurements
Separate close-range perceived strength, which facet leads, and detectability by another person. A declining total intensity can coincide with a woody facet becoming more prominent. Someone else may still detect fragrance after you adapt to it. Put these observations in different columns instead of compressing them into one 'lasting' score.
Use consistent checkpoints
Check at approximately 5, 30, 60 and 180 minutes, adjusting to your experiment. Keep dose, surface and sniffing distance comparable; avoid constant sniffing that increases adaptation. Record changed conditions such as warmer weather or handwashing. Consistent checkpoints matter more than assigning every note a universal lifespan.
This diagram illustrates air-driven atomization and liquid pickup. Not every perfume pump uses this exact mechanism; distinguish spray formation from scent chemistry.
Open full-size image ↗Why the opening cannot be replayed
Two-hour dry-down is not merely a quieter version of the opening. Evaporation and perceptual adaptation have changed the mixture. Spraying again onto the old blotter creates a different test because new material overlays residues. To compare clean openings, use a fresh test strip rather than topping up the used one.
Worked citrus-and-wood example
In a hypothetical test, citrus starts at 4/5 and woods at 1/5. An hour later citrus is 1/5 and wood feels like 3/5 while overall intensity has fallen. Wood becoming the dominant impression does not establish a chemical increase in wood content; relative prominence and perceived intensity are not concentration measurements.
Explain outcomes with calibrated confidence
If a wearer stops noticing the perfume while a second observer still detects it, sensory adaptation or observer differences may explain the discrepancy. One test does not establish universal longevity. Repeat on another day, and distinguish skin results from fabric results because they are different testing conditions.
Practice challenge
Track one perfume at 5, 30, 60 and 180 minutes. Record perceived intensity, leading character and, if possible, a fresh observer's detection.
Key concept map
Fragrance evolution chart
- Opening: first impression
- Heart: combined facets
- Dry-down: remaining effects
- Confounders: adaptation and surface
Observation notebook
- Fixed checkpoint
- Intensity from 1–5
- Leading impression
- Fresh observer feedback
Try the analysis on SESH fragrances
These are optional references for comparison, not evidence of a specific ingredient or superiority claim.
Further reading
The Perfume Society: fragrance FAQs · IFRA fragrance standards
