Eau de toilette, eau de parfum and extrait are useful market signals, but their names do not guarantee a universal oil percentage or a fixed number of hours on skin. Concentration, formula architecture, solvent system, spray output and wearing conditions work together. Brands should define a measurable finished specification instead of selecting a label first.
Use names as positioning, not laboratory shortcuts
Market conventions often place EDT below EDP and extrait in intensity, yet there is no single global percentage table that makes every product behave alike. Two fragrances at the same compound level can project and persist differently because their raw materials evaporate at different rates.
Compare prototypes on an equal basis
Ask for coded samples in the intended base and spray package. Apply the same number of sprays to blotters and a small wearer panel, then record opening, projection, character and dry-down at agreed intervals. Do not compare one sample freshly mixed and another fully rested.
Concentration changes more than strength
- A higher level can change clarity, colour and cold stability.
- Top notes may feel less expansive while the base becomes denser.
- Skin feel, staining risk and regulatory limits may change.
- Cost rises with compound level but performance may not rise proportionally.
- Pump dose and bottle size affect the consumer's real use pattern.
Write a release specification
Record fragrance code and revision, target concentration convention, alcohol or carrier specification, permitted appearance range, fill volume, pump reference and approved comparison sample. Run compatibility and stability work in the saleable pack. The name on the carton should describe the product actually evaluated.
Choose the format from the wearing occasion
An airy daytime launch may benefit from lift and repeat spraying; an extrait concept may prioritize closeness and texture. Test the commercial story with target customers before expanding sizes. The right concentration is the lowest-complexity formula that delivers the intended experience consistently—not automatically the highest number a manufacturer can fill.