Short answer
This glossary defines sixty terms used in perfume formulation and lab records, from absolute to volatility, in plain language. Where a term has a fuller explanation elsewhere on this blog, the definition links to it. Several words are used loosely in perfumery — "concentrate", "dilution" and "fixative" among them — so the definitions also say how they are used in our articles.
A–B
- Absolute
- A concentrated natural extract obtained by washing a concrete (or resinoid) with alcohol and removing the alcohol. Used for delicate flowers such as jasmine and tuberose. See essential oils, absolutes, resinoids and isolates.
- Absolute % (absolute percentage)
- A material's pure weight divided by the formula's total weight. It tells you how concentrated the material is in the mixture, counting solvent in the total. See formula %, absolute % and relative %.
- Accord
- A small blend of materials balanced so that they read as one new impression. See fragrance accords explained.
- Aldehydes
- A class of chemicals; in perfumery, especially the fatty aldehydes (C-10, C-11, C-12 and others) known for bright, waxy, sparkling effects. Many are used in small amounts and in dilution.
- Allergen (fragrance allergen)
- A fragrance substance that can cause skin sensitization in some people. In the EU, listed fragrance allergens must be named on cosmetic labels above set thresholds. See EU fragrance allergen labelling.
- Amber
- A warm, resinous, often sweet fragrance family or accord, typically built from vanillic, balsamic and labdanum-type materials. Not related to fossil amber.
- Aroma chemical
- A single fragrance molecule or a defined mixture used as a perfumery material, whether it also occurs in nature or not.
- Base
- A ready-made blend used as one ingredient in larger formulas; similar to an accord, often more elaborate, sometimes sold commercially.
- Base note
- The least volatile materials in a perfume, noticed in the drydown and lasting longest. See top, middle and base notes.
- Blotter
- A strip of absorbent paper used to smell materials and perfumes; also called a smelling strip or mouillette.
C–D
- CAS number
- The identifier assigned to a chemical substance by the Chemical Abstracts Service. Useful for identifying single chemicals, less so for natural extracts. See fragrance material names and CAS numbers.
- Chypre
- A traditional fragrance structure of a citrus top over a mossy, woody, labdanum base, named after a historical perfume.
- CO2 extract
- A natural extract obtained with carbon dioxide under pressure as the solvent; often closer to the raw material's smell than a distilled oil.
- Concentrate
- The blend of fragrance materials before it is diluted into a finished product; also called fragrance oil, compound or juice. In our articles it includes any solvent that came in with diluted ingredients.
- Concrete
- A waxy extract made by washing plant material with a solvent such as hexane; the intermediate from which an absolute is made.
- Diffusion
- How far and how readily a perfume or material spreads into the air around the wearer; related to, but not the same as, strength.
- Dilution
- Of a material: the share of a weighed solution that is the material itself, by weight. "Ambroxan 10%" is 10 g of Ambroxan per 100 g of solution. See how to dilute aroma chemicals.
- Dipropylene glycol (DPG)
- A nearly odorless, low-volatility solvent commonly used to dilute perfumery materials.
- Drydown
- The later stage of a perfume's evaporation, when the base notes dominate.
E–F
- Eau de cologne
- A light perfume, commonly around 2–5% concentrate, often citrus-led. In US usage, "cologne" is also used for any men's fragrance.
- Eau de parfum (EDP)
- A perfume strength commonly placed around 15–20% concentrate. The ranges are conventions, not legal definitions. See how to calculate perfume concentration.
- Eau de toilette (EDT)
- A perfume strength commonly placed around 5–15% concentrate.
- Essential oil
- A volatile natural extract obtained by steam or water distillation, or by expression in the case of citrus peels.
- Evaluation
- The structured smelling of materials or trials, at set time points and in comparison. See how to evaluate a perfume formula.
- Extrait (parfum)
- The strongest common perfume strength, often 20–30% concentrate or more.
- Fixative
- A low-volatility material used partly to slow the evaporation of others and extend a perfume's life. See perfume fixatives explained.
- Formula % (formula percentage)
- A row's weighed amount divided by the formula's total weight: its physical share of the mixture, solvent included.
- Fougère
- A traditional fragrance structure built around lavender, coumarin and moss-type notes.
- Fragrance family
- A group of perfumes or materials with a shared character, such as citrus, floral or woody. See fragrance families explained.
- Furocoumarins
- Compounds found in some citrus oils, notably bergapten in bergamot, that can cause phototoxic reactions; restricted under the IFRA Standards. "FCF" oils have had them removed.
G–I
- Gourmand
- A fragrance family of edible-smelling notes: vanilla, caramel, chocolate, fruit.
- Headspace
- The air above a liquid in a container. Large headspace means more oxygen and faster oxidation; also the name of a technique for capturing the scent around a living flower or object.
- Heart note
- A middle note: the materials that form a perfume's main character after the top notes fade.
- IFRA
- The International Fragrance Association, which publishes the IFRA Standards restricting or prohibiting certain fragrance materials. See the IFRA Standards guide.
- IFRA certificate
- A supplier's statement that a fragrance mixture conforms to a stated amendment of the IFRA Standards, with maximum use levels by product category. See IFRA certificates of conformity.
- INCI name
- The International Nomenclature of Cosmetic Ingredients name used on cosmetic ingredient lists.
- Internal solvent
- The solvent carried into a formula by diluted ingredients. It is part of the formula's weight but not of its scent.
- Isolate
- A single component separated from a natural material, such as linalool from an essential oil.
M–P
- Maceration
- Resting a diluted perfume after mixing so that it settles before evaluation or filling. See perfume maceration and aging.
- Maturation
- Resting the undiluted concentrate before dilution. The two terms are often used interchangeably.
- Mod (modification)
- A modified version of a formula submitted for evaluation, usually labeled A, B, C or by number. See tracking fragrance mods and samples.
- Modifier
- A material added in a small amount to shape an accord or formula without dominating it.
- Musk
- A family of soft, sensual, long-lasting materials; today almost always synthetic.
- Note
- A distinguishable impression in a perfume ("a rose note"). Notes on marketing pyramids are descriptive, not ingredient lists.
- Olfactory fatigue
- The temporary loss of sensitivity to a smell after exposure to it; a reason to take breaks when evaluating.
- Parts per thousand (ppt, ‰)
- Expressing a formula as shares of 1000. See parts per thousand in perfume formulas.
- Perfumer's alcohol
- High-strength ethanol sold for perfumery, usually denatured.
- Phototoxicity
- A skin reaction triggered when certain substances on the skin are exposed to sunlight; the reason some citrus materials are restricted.
- Pure active
- The weight of the material itself in a formula row: weighed amount × dilution. One gram of a 10% solution carries 0.1 g of pure active.
- Pyramid
- The model of a perfume as top, middle and base notes.
R–Z
- Relative % (relative percentage)
- A row's pure active divided by the total pure active of the formula: its share of the scent itself, ignoring solvent.
- Resinoid
- An extract of a resinous natural material such as benzoin or labdanum, typically viscous and long-lasting.
- SDS (safety data sheet)
- A supplier document describing a material's hazards and safe handling. See SDS, specifications and CoAs.
- Solvent
- A liquid used to dilute materials or the finished perfume, such as ethanol, DPG or isopropyl myristate.
- Substantivity
- How well a fragrance material persists on a substrate such as skin, hair or fabric, especially after washing.
- Tenacity
- How long a material or perfume remains perceptible, typically measured on a blotter.
- Top note
- The most volatile materials, dominating the first minutes of a perfume.
- Trial
- One physical making of a formula version for evaluation, usually small.
- Version
- A numbered state of a formula. Any change to materials or amounts makes a new version. See perfume formula version control.
- Volatility
- How readily a material evaporates; the physical basis of the perfume pyramid.
How these terms fit together
Most of these words describe one of three things: the materials (absolutes, isolates, aroma chemicals), the structure of a perfume (notes, accords, families), or the arithmetic and records that hold a formula together (dilution, pure active, versions). The perfume formulation guide introduces all three in order and links to the detailed articles.
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.