Choosing the Right Thinning Ratio: 30%, 45%, or 80% Teeth?
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Thinning scissors are one of the most misunderstood tools in professional grooming. Ask a room full of groomers which thinner they prefer and you'll get a dozen different answers — because the right choice genuinely depends on what you're trying to achieve. This guide breaks down thinning ratios so you can make a confident, informed decision.
What Is a Thinning Ratio?
The thinning ratio refers to the percentage of the blade that is made up of teeth, versus the gaps between them. A 30% thinner has fewer, wider-spaced teeth — removing less hair per pass. An 80% thinner has many closely-spaced teeth — removing more hair per pass and leaving a smoother finish.
This is sometimes expressed as tooth count (the number of individual teeth on the blade) rather than a percentage, but the principle is the same: more teeth = more blending, less bulk removal.
30% Thinning Scissors — Bulk Removal and Shaping
A low-ratio thinner like the UTSUMI PA30 is a powerful tool for removing bulk from thick, dense coats. With fewer, wider-spaced teeth, each pass through the coat removes a significant amount of hair while leaving a natural, textured finish.
Best used for:
- Removing bulk from double-coated breeds (Huskies, Golden Retrievers, Border Collies)
- Initial shaping and de-bulking before finishing
- Creating texture and movement in longer coats
- Thinning thick, coarse coats where a smooth finish isn't the goal
What to expect: The finish will show some texture and layering — this is intentional. A 30% thinner is not designed to blend seamlessly; it's designed to remove volume efficiently.
45% Thinning Scissors — The Versatile Middle Ground
A mid-ratio thinner sits between bulk removal and blending, making it one of the most versatile tools in a groomer's kit. The UTSUMI UA 70/45 (70mm blade with 45% tooth ratio) is an excellent example — capable of both shaping and blending depending on technique.
Best used for:
- Blending scissor lines on medium-coated breeds
- Softening transitions between different coat lengths
- General-purpose thinning on a wide range of breeds
- Groomers who want one thinner that can do most jobs
What to expect: A more blended finish than a 30% thinner, with good bulk removal. This is the ratio most professional groomers reach for first.
80% Thinning Scissors — Seamless Blending and Finishing
A high-ratio thinner like the UTSUMI UA 70/80 is a finishing tool. With closely-spaced teeth, it removes very little hair per pass but blends with exceptional precision — leaving a smooth, natural finish that's virtually undetectable.
Best used for:
- Final blending and finishing on show dogs
- Softening scissor marks and lines
- Blending on fine, silky coats (Yorkies, Maltese, Spaniels)
- Achieving a hand-stripped appearance on wire-coated breeds
- Detailed work around the face, ears, and feet
What to expect: Minimal bulk removal — this is not the tool for de-bulking. Used correctly, an 80% thinner leaves a finish so natural it looks like the coat grew that way.
Thinning Ratio Quick Reference
| Ratio | Tooth Count | Bulk Removal | Blending | Best Coat Types |
|---|---|---|---|---|
| 30% (e.g. PA30) | Low | High | Low | Thick, double coats |
| 45% (e.g. UA 70/45) | Medium | Medium | Medium | Most breeds, general use |
| 80% (e.g. UA 70/80) | High | Low | High | Fine, silky, show coats |
Do You Need More Than One Thinner?
Most professional groomers benefit from having at least two thinners — a lower ratio for bulk removal and a higher ratio for finishing. A common professional combination is a 30–45% thinner for shaping and an 80% thinner for blending and finishing work.
If you're starting out and can only invest in one, a 45% thinner is the most versatile choice — it handles the majority of grooming situations competently.
Blade Length Also Matters
Alongside the tooth ratio, blade length affects how the thinner performs. Longer blades (like the 70mm UA series) cover more coat per pass and are ideal for larger breeds and body work. Shorter blades offer more control for detailed work around the face and legs.