Vat dyes are a class of dyes with exceptional colour fastness, particularly to washing and light. They're called "vat" dyes because of the vat (container) used in the traditional dyeing process.
How They Work
Vat dyes are:
- Insoluble in water (won't dissolve)
- Chemically reduced to a soluble form
- Applied to fabric in this reduced state
- Oxidised back to insoluble form inside the fibre
The insoluble dye is trapped within the fibre - it literally can't wash out.
Properties
- Exceptional wash fastness
- Excellent light fastness
- Limited colour range
- Complex process
- Higher cost
Common Examples
Indigo: The classic vat dye used for denim.
In Towels
Vat dyes are less common than reactive dyes for towels because:
- Limited colour options
- More expensive process
- Reactive dyes are sufficient for most purposes
When used, they indicate premium quality and exceptional durability.
Related Terms
- Reactive dye - More common alternative
- Colour fastness - The benefit