Thinning
Cutting techniques
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Technique labels can cover different curricula; identify the implementation before visualizing or attempting the action. Apply to Thinning
- 01 Source the method Identify educator, curriculum, terminology, and competency.
- 02 Map the material Define section, state, tension, guide, preserve areas, and consent.
- 03 Verify the tool Use only the exact configuration and motion taught for the implementation.
- 04 Release and review Work conservatively, reassess, and stop at uncertainty or lost control.
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Description
Thinning reduces bulk using thinning shears or texturizing scissors. Learn tooth counts, thinning rates, placement, and how to avoid common thinning mistakes.
Thinning (セニング)
Quick look
- What it is: Reducing bulk and density using toothed scissors (thinning shears or blending shears)
- Also called: Sening (セニング) in Japanese salon terminology
- Key requirement: Choosing a model whose published cut rate suits the job
- Tool: Thinning shears with specific tooth profiles
Why it matters
Thinning is the primary method for removing bulk without changing shape. A well-executed thinning pass takes out interior weight while preserving the outline. Done poorly, it creates holes, shelf lines, and that dreaded “moth-eaten” look. The difference comes down to cut rate, tooth design and placement.
Tooth count alone does not tell you how much hair comes out. Use the maker’s published cut rate for that exact model (see Tooth Types); Joewell lists its 40-tooth E-40 at 35% and the 30-tooth E-30 at 15%. Those two figures do not generalize into a count rule, and comparing the 40-tooth and 30-tooth models shows why that gap stays model-specific.
Recommended scissors
| Feature | Recommendation |
|---|---|
| Type | A toothed shear: usually one toothed blade against a straight blade; some models have teeth on both blades, whatever the maker calls them |
| Cut rate | Match the maker’s published rate to your most common need |
| Tooth profile | See tooth tip profiles for V-shaped vs. U-shaped vs. flat options |
| Size | Your choice by reach and tip control (Scissor Sizes) |
Technique notes
Placement is where most mistakes happen. Three working rules from the sources:
- Never thin the perimeter (アウトライン); the flyaways are uncontrollable.
- Never thin within 2 to 3 cm of the part line or the crown whorl; short hairs poke through the surface.
- Never run root to tip in one continuous stroke; density comes out inconsistent.
In the interior, keep the work roughly 2 to 4 inches off the root on mid-length hair so support is not stripped where volume lives.
Close the shears once per section, then release. Do not “chatter” (rapidly opening and closing) in the same spot. Each closure removes a percentage of hair from that exact location, and multiple closures stack into visible gaps.
Match removal to the job rather than to a count: start conservatively and make another pass if the design needs it, and choose a higher rate only where the result can carry more visible texture.
Japanese thinning technique often involves “sening” (セニング) in specific patterns across the head. The pattern controls where weight lives in the finished shape. Position then sets the effect: roots control support and volume, mid-lengths redirect flow, and tips soften or blend.
Related links
Related guide: Tool Mastery: Thinning Cut Rates
Sources
- KAMIU (kamiu.jp) thinning shear selection and technique guides
- Joewell Scissors tooth design technical documentation
- Hikari Scissors professional education materials on sening technique
See Also
Frequently Asked Questions
3 answers you can open one at a timeDoes tooth count tell you the thinning cut rate?
No. Tooth count alone does not tell you how much hair comes out, because tooth width, spacing, groove and comb-blade shape change the result. Use the maker’s published cut rate for that exact model: Joewell lists its 40-tooth E-40 at 35% and its 30-tooth E-30 at 15%, while its 30-tooth families also include approximately 20% and 30% models.
Where should you avoid thinning on the head?
Three working rules from the sources: never thin the perimeter, because the resulting flyaways are uncontrollable; never thin within 2 to 3 cm of the part line or crown whorl, because short hairs poke through the surface; and never run root to tip in one continuous stroke, which leaves inconsistent density. In the interior, keep the work roughly 2 to 4 inches off the root on mid-length hair so support is not stripped where volume lives.
What's the Japanese sening approach to thinning?
Japanese thinning technique (セニング, sening) places the tool in specific patterns across the head rather than at random. The pattern controls where weight lives in the finished shape. Position then sets the effect: roots control support and volume, mid-lengths redirect flow, and tips soften or blend. Pair the pattern with the maker’s published cut rate for the exact model and the client’s hair rather than with a count rule.
Comments & questions
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