In short
Perfumery materials fall into a few practical types: essential oils from distillation or pressing, concretes and absolutes from solvent extraction, resinoids from resins, CO2 extracts, tinctures, natural isolates, and synthetic aroma chemicals. How a material is produced affects how it smells, how it handles at the bench and how it should be stored.
What you will learn
- Name the main types of perfumery material and how each is produced
- Predict the practical handling issues each type brings
- Choose sensible types for a first collection
Before this lesson: Natural and Synthetic Materials, Side by Side
The types, side by side
| Type | Made by | Usually feels like | Bench note |
|---|---|---|---|
| Essential oil | Distillation, or pressing for citrus | Thin liquid, often bright | Easy to pipette. Some oxidize readily. |
| Concrete | Solvent extraction of plant matter | Waxy solid or paste | Rarely a beginner's material |
| Absolute | Alcohol wash of a concrete | Thick, dark, rich, close to the source | Often viscous. Usually costly. Dilute it to use it. |
| Resinoid | Solvent extraction of resin or dried matter | Very thick or solid | May need warming or pre-dilution |
| CO2 extract | Pressurized carbon dioxide | Varies, can be close to the raw plant | Some are waxy, so check the supplier's notes |
| Tincture | Steeping in alcohol | Thin, weak, sometimes deep | Often home-made. Strength is hard to define. See our tincture guide. |
| Natural isolate | Separated from a natural source | One clear smell | Handle as for an aroma chemical |
| Aroma chemical | Chemical synthesis | Liquid or crystals, one main smell | The next lesson covers these |
For a fuller reference comparing these, including the differences between oil and absolute for one plant, read essential oils, absolutes and isolates. The RUŌOD Journal explains extraction for general readers. This lesson focuses on what the types mean when one is in front of you.
One plant, different materials
A single plant can give several materials that smell quite different. Lavender oil is distilled, and it reads fresh and herbal. Lavender absolute comes from solvent extraction, and it reads darker and more hay-like. The word lavender therefore does not tell you what you will get. Always check the type, and record it.
Natural materials also vary with species, origin, harvest and processing. Some plants even occur in chemically different types, called chemotypes. So your notes should say where a sample came from as well as what it is called.
What type tells you in practice
- Viscosity. Thick materials are hard to pipette accurately. You will usually weigh them directly, or use them as a pre-made dilution.
- Solubility. Waxes in some extracts can leave a cloudy dilution. Cloudiness is not necessarily a fault in a study sample, but note it.
- Color. Dark absolutes and resinoids can stain paper and discolor a finished product.
- Cost. Absolutes are often far more expensive. Buy a very small amount, or buy a pre-diluted version.
- Stability. Citrus oils and some other terpene-rich oils are prone to oxidation, as the storage lesson explains.
What to begin with
For a first set, thin essential oils and a few simple aroma chemicals are easier and cheaper than absolutes and resinoids, and they teach you more quickly. Add one absolute later, so that you learn what the category feels like. The last lesson of this level helps you choose a training library.
Be careful with the words fragrance oil and perfume oil. They usually mean a ready-made blend, not a single material, and the seller may not tell you what is in it. A blend is fine for some projects, but it will not teach you what a material smells like, and the guide to fragrance oils versus formulating explains the trade-offs.
Practical exercise: Classify what you already own
- List every aromatic thing you own or plan to buy: oils, samples, spices and fragrances.
- Sort them by type using the table. Mark anything you cannot classify as unknown blend. That is a useful finding in itself.
- For each one, write its likely handling issue: thin, thick, staining, oxidation-prone or costly.
- Look up one of your materials in the material encyclopedia, and check whether its type matches what the seller called it.
You have done this well if each material in your collection is assigned a type with a reason, and any disagreement with a seller is recorded together with your source.
Common mistakes
- Assuming one name means one material. Rose oil, rose absolute and a rose fragrance oil are three very different things.
- Buying absolutes first. They are costly and hard to handle, and a beginner often cannot read them yet.
- Trusting labels such as "100% pure". Purity claims are not always reliable, and adulteration is a real issue. Buy from suppliers who provide documents.
Key terms
- Essential oil
- A volatile natural material obtained by distillation or, for citrus peels, by mechanical expression.
- Concrete
- A waxy solvent extract of plant material, the intermediate from which an absolute is made.
- Absolute
- An alcohol-soluble extract obtained by washing a concrete with alcohol and removing the waxes.
- Resinoid
- A solvent extract of a resin or other dried natural material.
- CO2 extract
- A natural extract made using carbon dioxide under pressure as the solvent.
- Tincture
- A natural material steeped in alcohol, which holds the extracted smell in solution.
Knowledge check
Written and reviewed by the RUŌOD Lab team. This is general education, not legal, regulatory, medical or safety advice. Example dilutions and exercises are for learning, are not validated products, and have not been safety-assessed. Completing a lesson confers no qualification. How we check these lessons.