Reactive dyes from India are sold mainly for cotton, viscose and other cellulose fibres, and disperse dyes from India for polyester and other synthetic fibres. They are the two largest dye classes made in Gujarat, and in both cases the order should name the Colour Index identity, the strength and the physical form.
If you are searching for dyes from India in general, start by deciding which fibre you dye. That decides the class, and the class decides the questions.
What should you specify for reactive dyes?
A reactive dye forms a chemical bond with the fibre, so fixation and wash fastness are the point. Read what reactive dyes are if you need the background. For the order itself, write down these items:
- The Colour Index name and number, so the supplier cannot substitute a similar shade.
- Strength against a named standard, usually stated as a percentage of the standard.
- Shade difference limit against your own reference sample.
- Physical form: powder, granule or liquid, and the dust or solubility requirement.
- Fastness to washing, light and rubbing, tested to the standard you use.
- Limits for moisture, insoluble matter and, where required, heavy metals.
What changes for disperse dyes?
Disperse dyes are applied as fine particles to polyester at high temperature, so particle size, dispersion stability and heat behaviour matter as much as shade. Disperse dyes explained covers the chemistry. Ask for the dispersing agent used, the particle size distribution, and the dispersion stability at your dyeing temperature, because a poor dispersion leaves spots on the fabric.
Disperse dyes also carry the fastness question to sublimation and to the other finishing steps in your mill. Tell the maker which processes follow dyeing.
How do you compare quotes fairly?
Dye quotes are only comparable at equal strength. A dye at 80% of standard strength needs more dye per kilo of fabric, so a lower quote can cost more in the dye house. Ask every supplier to state strength against the same standard and compare cost per unit of colour, not per kilo. Our guide to writing a reactive dye specification shows how to set this out.
What compliance questions come up?
Buyers who supply international brands will often need the dye to meet restricted-substance lists, including limits on certain amines. Ask each supplier what it can document before you place a trial order. See Indian dyes and ZDHC MRSL for the approach. Requirements vary by brand and by market, so confirm them with your customer or certifier.
How do you test before the full order?
Dye a lab-scale trial with the sample, against your standard, on your own fabric and process. Check shade, strength and fastness, then ask for a second batch to test consistency. A single good batch tells you very little. The same sample-then-batch routine applies to every dye order.
Next step
We find Gujarat dye makers that suit your class and volume, audit the plant, check the samples and have each lot tested before dispatch. Our fee is one written amount agreed in advance, and we work only for you. Book a free sourcing review, or read more about why Gujarat supplies dyes and pigments.