Reactive dyes form a chemical bond with cellulose fibres such as cotton, so the colour becomes part of the fibre and gives good wash fastness and bright, clear shades. Pigments do not bond at all; they are insoluble colour particles held on the fabric surface by a resin binder, which gives a flatter, softer-looking result that is cheaper but less fast to washing and rubbing. Both are used in high volume by Indian processing houses around Ahmedabad, and the choice should follow the end use and the fastness your customer expects. A buyer who specifies only the colour, and not the dye class, often ends up with pigment when reactive was assumed.
How each process works
In reactive dyeing the fabric is padded or exhausted with the dye, alkali fixes it by reaction with the cellulose, and the unfixed dye is then washed off in several rinses. The washing-off stage uses a good deal of water and energy, which is part of the cost. Pigment dyeing is a pad-dry-cure process: the fabric is padded with pigment and binder, dried, then cured with heat so the binder films over the surface. There is no washing off, so the process is quicker, uses less water, and works on blends as well as on cotton because the pigment does not need any affinity for the fibre.
Comparing the two
- Wash fastness: reactive is usually good, typically grade 4 or better; pigment depends heavily on binder quality and often falls a grade lower.
- Rubbing fastness: pigment is more prone to crocking, especially in dark shades and after a peach finish.
- Shade range: reactive gives brighter and deeper shades; pigment shades are more muted, and heavy shades are hard to achieve.
- Handle: pigment binders can stiffen the fabric, although modern binders and softeners reduce this.
- Cost: pigment is usually the cheaper route, particularly for pale and medium shades and short runs.
- Look: pigment gives a washed, vintage or garment-dyed appearance that some brands want, and it fades evenly.
- Blends: pigment works across fibre types; reactive needs cellulose, so polyester cotton usually needs a two-stage process.
Which to choose
For shirting, bed linen, children's wear and anything that will be laundered often, reactive dyeing is normally the right call, and the extra cost is small against the risk of complaints. For promotional bags, home decor, garment-dyed looks and products that see few washes, pigment is often adequate and keeps the price down.
Whatever you choose, write the dye class into the specification and ask for a fastness report on the bulk shade, not just on the lab dip. For both routes, ask whether the process house works to ZDHC input limits and holds an OEKO-TEX or GOTS certificate if your market needs one.
How Creston & Co helps
We confirm the dye class at the process house, not just on paper, and send sealed bulk samples to an NABL-accredited lab for wash and rubbing fastness before any roll is loaded. We inspect rolls, supervise loading and send weekly updates. If you are unsure whether reactive or pigment suits a new product, a free 20-minute sourcing review will settle it quickly.