Why We Made Two Oils Instead of One

No.115 and No.215 have the same five ingredients, in the same order, on the label. They are still two different products, sold separately, and we get asked fairly often why we did not just make one bottle and tell people to use more or less of it. This page is the answer: what the raw-material testing actually involved, why one formula could not cover both jobs, and what we changed to get from one to the other.

The problem we hit

We set out to make one finishing oil for the salon — light enough to spray on almost anyone, from the roots down, without weighing the hair or leaving residue. That worked for fine and normal hair. It did not do enough for the clients whose hair is thick, stiff, and will not settle: the same formula that disappeared on fine hair was not enough to soften and hold down hair that springs back the moment you stop working it.

The obvious fix was to make the single formula richer. That traded one problem for the other — rich enough to settle stubborn hair was too much for fine hair, which went flat by the middle of the day. We spent a while looking for a middle setting that served both groups.

What ended that search was not a measurement. Colleagues at the salon — working hairdressers, using the samples on their own clients — had been testing alongside us, and their preferences never converged. They split into two camps and stayed there. No.215 exists because one of them kept asking for it: not a heavier dose of the light version, but a different balance, for the hair they had in the chair every day. When the people using something daily cannot agree on one setting, that is not a formulation problem still waiting to be solved. That is the answer.

What we tested

Before the split question came up at all, there was a long stretch of simply choosing raw materials. This is the part of the story we are most confident about, because it happened in the salon on real heads rather than on paper.

Two oils that carry the same INCI name are not the same oil. That single fact is what made this slow, and it is the part of the project we underestimated most. An ingredient list gives you a name — Cyclopentasiloxane, Argania Spinosa (Argan) Oil — and two suppliers can both put that name on a drum and send materials that behave differently on hair. Not marginally differently. Differently enough to tell apart once the hair is dry.

The practical consequence was that we could not choose suppliers the way a small brand normally chooses them. Price per gram, minimum order size, how easy a company is to work with — none of that could make the decision, because the cheaper drum and the more expensive drum carry the identical name and nothing on paper separates them. So we tested each supplier's version of each ingredient on hair, and let that decide. It took more than two years, spread across normal salon work, and a long list of suppliers did not survive it.

The two things we judged against were whether the oil absorbed rather than sat on the surface, and whether the hair still moved on its own afterward. Richness was not one of the criteria. A sample could feel luxurious in the hand and still be rejected for leaving the hair stiff or lifeless.

One supplier's cyclomethicone came out clearly ahead of the rest. It was not a close call, and both No.115 and No.215 are built on it.

The part we cannot prove

Our working explanation for that difference is about what stays behind, not what evaporates. A volatile silicone base does not leave completely; a very small non-volatile fraction remains, and the supplier's specification sheet gives an upper limit for it. We think that small remainder does more than its size suggests, and that it is what separated the materials we tried.

We have not measured this. We compared results on hair, which is the test that matters most to a hairdresser and the weakest kind of evidence for a mechanism. Other things could explain it — purity, the ratio of related molecules, trace impurities — and we have not separated those variables. We wrote this out at more length, including a claim we removed from our own product page, in what "weightless" actually means in a hair oil.

Why one formula was not enough

The two problems pull in opposite directions. Volume in fine hair is almost entirely the first inch lifting away from the scalp, and it does not take much sitting on that inch to lose it. Thick, stiff hair has the reverse problem: it holds its own shape too well, and it needs something with enough substance to talk it down.

A single formula sits at one point on that scale. Move it toward the fine-hair end and it stops helping stubborn hair; move it toward the other end and fine hair goes flat. We never found a middle setting that satisfied both groups, and the people testing it were the ones telling us so. That is the whole reason there are two bottles. We describe those two problems on their own pages: fine hair that gets weighed down and stiff hair that won't lay flat.

What "recalibrated" means

No.215 is described as the same lightweight DNA as No.115, recalibrated. In plain terms: the base and the ingredient list are the same, and what shifts is the balance between the part that evaporates and the part that stays — moved slightly toward what stays. Enough to soften and settle stubborn hair; not enough to make it heavy.

We keep this deliberately non-numeric. The quantity involved is small, the specification we work to is an upper limit rather than a guarantee, and putting a figure on the front of a bottle would say more than we actually know. What we can say is directional: No.215 leaves a little more on the hair than No.115 does, on purpose.

How this shows up in the two products

Short version, if you are trying to choose:

  • No.115 — fine to normal hair. Protection and finish with nothing you can feel. Spray from the roots down before blow-drying.
  • No.215 — thick, stiff, hard-to-settle hair, including hair that is too straight to hold a shape. Same use, slightly more left on the hair.

Both are sprayed onto towel-dried hair, both contain no water, and both can be used on dry hair before a flat iron for that reason. Neither one adds body or holds a style — they protect and finish, they do not build.

⚠ A note for your safety: these products contain organic Argan Oil. If you have a known nut allergy, please consult a professional or perform a patch test before use.

FAQ

Q. Can I just buy No.115 and use more of it on stiff hair?
A. You can, and some people do, but more of a formula built to disappear is still a formula built to disappear. No.215 is a different balance, not a larger dose.

Q. Are the ingredient lists really identical?
A. Yes — the same five ingredients in the same order. The difference is in proportions, which is not something an ingredient list shows.

Q. Which one should I get if I am in between?
A. Go by the individual strand. If each hair is fine and soft, No.115. If the strands themselves are thick and stubborn, No.215, regardless of how much hair you have.

Q. Did it really take two years?
A. The raw-material testing did, spread across normal salon work rather than done all at once. Choosing between suppliers who all pass on paper is slow when the only real test is on hair.

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Written by Marcy Hasegawa, hairdresser in San Francisco (Hair Caffe). Last updated: September 1, 2026.