Short answer
To track fragrance mods and samples, give every sample a unique code that maps to an exact formula code and version, record what each mod changed from its predecessor, log who received which samples and when, record feedback against the version (not the sample label), and keep the decision trail through to the final choice. A simple submission log — one row per sample sent — is enough for most small businesses and prevents the classic failure: a client loves "mod C" and nobody can say exactly what mod C was.
What a mod is
In fragrance development, a mod (modification) is a variant of a formula submitted for evaluation. Mods are often labeled with letters (A, B, C) or numbers within a round, so that evaluators judge the smell rather than the history. That anonymity is useful for evaluation and dangerous for record-keeping: the label means nothing on its own. Every mod label must map to a specific formula code and version.
Codes that cannot be confused
Use a sample code that is unique across projects and rounds, not just "A" — for example project code, round and letter: "P14-R2-C". Keep the map in one place:
| Sample code | Formula | Version | Change from previous round | Strength |
|---|---|---|---|---|
| P14-R2-A | EX-031 | v9 | Reference: round 1 favorite, unchanged | 18% |
| P14-R2-B | EX-031 | v10 | Bergamot +20%, to brighten the opening | 18% |
| P14-R2-C | EX-031 | v11 | Musk −25%, cleaner drydown | 18% |
Including the previous favorite unchanged as one of the samples gives every round a fixed point of comparison.
The submission log
One row per sample sent:
- Sample code and the formula code and version it contains.
- Recipient and date sent.
- Format and quantity (blotters, 2 ml spray, etc.) and strength.
- Date the sample was made, and its age when evaluated, if known.
- Feedback received, with the date.
- Decision: selected, rejected, or modify further.
Sample age matters: a freshly made mod and one that has rested for three weeks can smell different, and comparing them is unfair to the fresh one. See perfume maceration and aging.
Recording feedback usefully
Feedback is most useful when it is specific and comparable. Give evaluators a short form: which they prefer, what they like and dislike, at which point in the wear, and how each compares with the reference. Record feedback against the formula version, so that "client preferred C in round 2" becomes "client preferred EX-031 v11", which is meaningful a year later. Turning feedback into the next set of changes is covered in how to adjust and refine a perfume formula.
Keeping mods and versions straight
Every mod is a version; not every version is a mod. Number versions continuously in the formula record, and treat sample codes as a separate layer on top. Never renumber versions to match sample letters, and never edit a version after it has been sent out — if it changes, it is a new version and a new sample. Perfume formula version control explains the numbering rules.
Closing the loop
When a mod is chosen, record the decision against the brief (see how to write a fragrance brief), mark the version approved, and lock it. Keep samples of the chosen mod and the runners-up, sealed and labeled, as references. The approval stage and what follows are described in building a fragrance development workflow.
In RUŌOD Lab, a formula's tags, notes and version number can carry the project and round, its status can move from Testing to Approved, and the approved version can be locked against deletion; the sample log itself is simple enough to keep in a note or a spreadsheet alongside.
Filling and labeling the samples themselves is covered in how to make perfume samples, and the records for one-client perfumes in bespoke perfume records.
Frequently asked questions
Should samples be blind?
For honest feedback, usually yes — evaluators should not know which is the "new" one. You, however, must always know.
How many mods should a round contain?
Few enough to evaluate properly — often two to four, including the previous favorite. More options mean more olfactory fatigue and vaguer feedback.
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.