Reactive dyes and why the colour holds

Short answer: Reactive dyes bond chemically to the cellulose fibre instead of sitting on the outside. That is why they fade slowly and only bleed in the first few washes.

What happens in the dye bath

In reactive dyeing a chemical bond forms between the dye and the fibre. The colour becomes part of the fibre rather than a layer on the surface. It is the most widespread method for cellulose fibres such as cotton and viscose.

Why colour still comes off

Not every molecule manages to bond. The rest is rinsed away in production and in the first couple of washes at home. That is why new dark clothes should be washed separately the first few times. See bamboo clothing for men.

What makes the colour disappear anyway

Sunlight, chlorine and high temperature break the bond down. Wash cool, dry in shade and keep bleach away, and the colour lasts markedly longer. See bamboo t-shirts for men and bamboo clothing for women.

Frequently asked questions

Why does black fade fastest

Because black needs the most dye and therefore has the most to lose before it shows.

Can a garment be redyed at home

Yes, with fabric dye for cellulose fibres. The result is most even on plain fabric.

Is the dye a problem for skin

OEKO-TEX certification tests exactly that, the finished fabric, for dye residues.