You took the course. You filmed the sequence, took the mannequin home, ran it three times and got good at it. The following Tuesday, the same movements on a real client gave you something else entirely: the side opened up, the fringe climbed two finger widths once it dried, and a point appeared at the nape that never existed on the mannequin.
People searching for a “haircut course for hairdressers” are usually standing exactly there. The hands are not the problem. What is missing is an explanation for the gap between the rehearsed result and the result in the chair.
That explanation is almost always the same one: the cut was copied, not designed.
Manual talent explains less than it seems to
The most common belief in this trade is that cutting is learned by volume: the more heads you cut, the better you get. That is partly true for dexterity and almost entirely false for decision making.
Practice consolidates what you already do, including what you do wrong. And the feedback loop in our profession is terrible: the client who disliked her cut rarely says so. She thanks you, pays, and does not come back. You never receive the piece of information that would have corrected the next one. Ten years under those conditions are not ten years of learning. They are ten years of repeating the same assumption.
The scissors only execute. The decision belongs to the reading you do before the first movement, and that reading has variables you can measure.
The strand decides before you do
A human hair strand usually measures between 50 and 100 micrometres across (a micrometre is a thousandth of a millimetre). Inside that narrow range live opposite behaviours: fine, dense hair accepts solid lines that thick, sparse hair turns into dead weight.
The cross section changes too. In straighter hair it tends towards round; in wavy and coily hair, towards elliptical and flattened. The geometry of that cross section is what creates the curl, and the curl is what decides where the length will stop once it dries.
Hence the number that ruins more cuts than any other: shrinkage. In tight curl patterns, the difference between wet length and dry length can exceed a third. If you cut at jaw level with the hair wet and stretched, the dry result can land close to the ear. The scissors did not climb. The strand went back where it belongs.
Average growth sits near 1 cm a month, and it varies from person to person. That is planning, not trivia: it decides whether your cut needs a return visit in six weeks or holds for four months, and the client is entitled to that information before she decides.
Tension is the most expensive mistake, and the only one invisible at the time
Wet hair stretches. When you comb, pull and cut, you are cutting a length that will not exist afterwards. Worse, the tension is never uniform. The section you hold closer to the scalp gets more traction than the one at the bottom of the nape, and the difference only shows up in the blow dry.
Cutting dry, or at least checking dry, is not an aesthetic preference. It is variable control. You start seeing the natural fall instead of deducing the natural fall.
The same logic applies to the crown whorl and to the implantation, the direction in which the hair emerges from the scalp. Brushing and product hide both. If the only head you ever see is an already styled one, you are designing a cut for hair that exists forty minutes a week.
Five readings before the first movement
| What you read | How you check it | What it changes at the scissors |
|---|---|---|
| Real curl pattern | loose strand, dry, no product, in side light | the cutting point rises to allow for shrinkage |
| Diameter and texture | touch in three regions, confirmed on trichoscopy | solid line, point cutting or internal weight removal |
| Density by region | strand count per cm² on the trichoscope | where volume fits and where volume reads as a gap |
| Implantation and whorl | dry scalp, no brushing | direction of the lines, the side the fringe opens to |
| Proportion of face, jaw and neck | thirds and jaw height measurements | the shortest viable length before the cut hardens the face |
Trichoscopy is an imaging assessment of the scalp and the strand under magnification of dozens of times. It counts and measures what the hand estimates out of habit. Here the trichoscope is part of the hair assessment, which costs R$200 (Brazilian reais, roughly the price of a single salon service) and is credited in full towards the protocol. But for you, as a professional, the point is a different one: the distance between thinking the hair got finer and watching the variation in diameter on the screen with the professional beside you.
Visagism, in this set of tools, is not picking a cut from a face shape table. It is deciding which reading of the face the cut is going to support, and accepting that some reference photos do not fit that particular combination of strand, implantation and proportion. Saying so during the consultation, with the technical reason in hand, costs far less than delivering the cut and losing the client in silence.
Where cutting does not solve it, and you need to recognise that fast
A good share of what arrives as “I want to change my cut” is actually shedding, thinning or a scalp in distress. Cutting redistributes weight and improves the perception of volume. Cutting treats nothing.
Flaking with persistent redness, pustules, pain or burning to the touch, well defined patches of loss, any suspicion of a scarred area: that is an appointment with a dermatologist, before any protocol and before any scissors. Referring someone out is not losing a client. It is the only defensible course of action, and clients notice the difference.
Between the cut and the doctor sits the territory of hair therapy, which has its own day here: Tuesday is reserved for it. Follow up is measured, not felt. We measure again during or at the last session and compare with the image from the first day, at no extra cost. That is the standard worth taking back to your own chair, with or without a course: if you do not measure it, you do not know it.
What fits into two days with four people
The in-person Cutting Technology class runs on 25 and 26 October 2026, with a maximum of four participants.
The cap is not positioning. It follows from the format: in two days, each participant puts their own hands to the scissors under observation, and that does not scale. In a room of thirty you watch a demonstration and leave with a video. With four, there is time to stop you mid movement, undo the assumption and rebuild the decision.
The content follows the order of this article: reading the strand and the scalp with trichoscopy as support, reading the face and proportion, writing out your cut plan before the first movement, execution, dry checking, and setting the return interval. It is led by Nelma Faleiro, specialist in cosmetic trichology, ten years as a university lecturer, winner of the SINVISA Trophy 2025, with research on chemically processed coily hair.
This is not a course about one haircut. It is a course about how to decide the haircut, which includes the least comfortable part of the job: holding a technical “no” in front of a reference photo.
If you would like to talk about your case
If you work behind the chair, have already taken courses, and feel the problem sits in the decision rather than in your hands, talk to us on WhatsApp before you enrol. Tell us who you serve today, the hair type that shows up most often in your chair, and where the result tends to get away from you. With only four places, it helps to know in advance who is coming.
The salon is in Tatuapé, in the East Zone of São Paulo, near the Carrão and Tatuapé metro stations, and we are open Tuesday to Saturday, 9am to 6pm, by appointment. The Cutting Technology class is on 25 and 26 October 2026.