Micronaire is a measurement of cotton fibre fineness and maturity, determined by air permeability testing. It's a key quality indicator in cotton grading.
The Scale
Micronaire values typically range from 3.0 to 5.5:
| Value | Interpretation |
|---|---|
| Below 3.5 | Fine, possibly immature |
| 3.5-3.9 | Fine, premium |
| 4.0-4.9 | Average, standard |
| 5.0+ | Coarse |
What It Measures
Micronaire combines two properties:
- Fineness: Fibre diameter
- Maturity: Cell wall thickness
Fine, mature fibres are ideal. Very low micronaire may indicate immaturity (weak fibres) rather than desirable fineness.
Why It Matters
Lower micronaire (within healthy range) indicates:
- Finer fibres
- Softer fabric
- Better dye uptake
- Premium quality
In Towels
Consumers rarely see micronaire values, but they affect the final product. Premium cotton varieties (Egyptian, Pima) typically have favourable micronaire readings.
Related Terms
- Staple length - Another quality measure
- Long-staple cotton - Premium category
- Denier - Synthetic fibre fineness