A blade is a sandwich of wood (and sometimes fibre) plies. Each layer's position and species changes how the whole blade behaves.
# Module 2 — Inside the Blade: Anatomy of Plies
A table tennis blade is an engineered composite — not a single piece of wood.
Standard blades are 5 or 7 plies. Each ply's position matters as much as its species.
## ITTF Regulation (Confirmed 2024–2026)
> "At least 85% of the blade's thickness must be natural wood. Each fibrous
> reinforcing layer must not exceed 7.5% of the total thickness, or 0.35mm,
> whichever is smaller."
The 0.35mm cap on each fibre layer is why carbon layers are so thin in approved blades.
A blade could use 15% composite — but not in one thick layer.
*(Source: Wikipedia citing ITTF Laws of Table Tennis, retrieved March 2026)*
## Standard 5-Ply Construction
```
[Outer ply — species A]
[Sub-outer ply — species B]
[Core — species C]
[Sub-outer ply — species B]
[Outer ply — species A]
```
### Example: Butterfly Petr Korbel / Primorac family
`Limba — Ayous — Limba` (5 plies, all symmetric)
The outer Limba gives good touch; the Ayous core is softer and provides
a longer dwell window at the heart of the blade.
## The Core Principle (Validated)
For standard offensive blades, the core is almost always softer than the outer plies.
This allows the outer layers to give initial crisp contact while the core
provides a secondary "cushion" that extends dwell.
**Exceptions:**
- Single-species blades (e.g., all-Hinoki blades — uniform throughout)
- Some stiff 7-ply designs where carbon layers adjacent to the core
make the core region stiffer, not softer (e.g., Stiga CC7 rated 8.9/10 stiffness)
## Common Wood Species (Cross-Validated)
| Species | Feel | Used As | Notes |
|---------|------|---------|-------|
| **Koto** | Hard, crisp | Outer ply | DHS Hurricane blades; contact always feels crisp |
| **Limba** | Soft, controlled | Outer ply, sub-outer | Butterfly's most common outer; spin-friendly |
| **Ayous** | Soft | Core | Softer than Limba; found in Korbel, Viscaria, countless others |
| **Hinoki** | Springy, resonant | Single species or outer | *Not simply "crisp"* — it is bouncy, fast, and vibro-acoustically unique; Japanese Cypress |
| **Walnut** | Hard | Outer/sub-outer | Higher density; less common in modern blades |
| **Kiri** | Very soft | Core in defensive blades | Galaxy Def-5 (softest on Revspin.net: 0.7/10 stiffness) |
> ⚠️ **Hinoki Note:** Unlike koto (surface hardness = crisp), hinoki has a
> high *elastic rebound* — the ball bounces off energetically. It is often
> described as "springy" or "pingy," not crisp. The distinction matters when
> choosing between Chinese and Japanese-style blades.