Mercerisation is a finishing process that treats cotton with sodium hydroxide (caustic soda) under tension. Named after John Mercer who discovered the process in 1844.
What It Does
Mercerisation permanently changes cotton fibres:
- Swells and straightens fibres
- Increases lustre (silky sheen)
- Improves dye uptake (more vibrant colours)
- Increases strength (up to 20%)
- Improves absorbency
The Process
- Cotton yarn or fabric is treated with concentrated sodium hydroxide
- Material is held under tension during treatment
- Alkali is washed out and neutralised
- Fibres remain permanently modified
Why It Matters for Towels
Mercerised cotton towels have:
- Better colour depth and vibrancy
- Improved strength and durability
- Slight silky sheen
- Enhanced absorbency
Quality Indicator
"Mercerised cotton" on a label indicates additional processing investment - a quality signal. Budget towels skip mercerisation to reduce costs.
Mercerised vs Unmercerised
| Mercerised | Unmercerised |
|---|---|
| Lustrous | Matte |
| Stronger | Standard strength |
| Better dye uptake | May fade more |
| More expensive | Cheaper |
Related Terms
- Cotton - Base material
- Combed cotton - Often combined
- Ring-spun - Often combined