A custom pigment dispersion is a pigment ground into a carrier at an agreed loading, to a stated fineness and shade. To order one from India you need to specify the pigment, the carrier system, the pigment loading and the dispersion quality, and then agree how each will be tested.
Vague briefs such as match this colour lead to rework. A short written specification avoids it.
What must the specification include?
- The pigment, named by Colour Index name and number, so that the supplier does not substitute a similar one. See the Colour Index number.
- The carrier: water, solvent, resin, plasticiser or oil, chosen to match your end system so the dispersion mixes without shock or incompatibility.
- Pigment loading, as percentage by weight, because it sets the colour strength per kilogram.
- Dispersant, binder and other additives, and any you cannot accept, such as certain solvents or preservatives.
- Fineness of grind or particle size, and the test that measures it.
- Viscosity range and storage stability, since a dispersion that thickens or settles is unusable.
How are shade and strength agreed?
Agree a standard: a physical reference sample that both sides keep, or a drawdown or moulded chip on your own base. Shade difference is measured with a spectrophotometer and expressed as a colour difference value, with a tolerance both sides accept; see dye shade matching tolerance for how tolerances are set.
Colour strength is compared to the standard in the same test system, such as a white-tint reduction, because strength differences show up quickly there. Test in your system, not only in the supplier's.
How is dispersion quality tested?
A good dispersion has pigment particles separated and stable. Poor dispersion shows as lost strength, specks, streaks, rub-up differences, low gloss or filter blocking. Common checks include a fineness-of-grind gauge, laser particle size analysis, filtration or pressure-rise tests, and microscopic inspection.
Read what dispersion quality is and how it is tested for how these tests work, and require results on every batch, together with the batch number.
For plastics colouring, heat stability may also matter; check the end process before choosing the pigment and carrier.
Orders, samples and minimums
Dispersions are made in batches, and the minimum depends on mill size and on how often the plant changes colour. Custom shades usually mean cleaning the mill, which raises the practical minimum; see the MOQ for custom dye shades, which follows the same logic.
Ask for a lab sample, then a pilot batch, then production. Keep a sealed retention sample of every approved batch to settle later disputes. Check the pigment against its application before you order.
Heavy metals and restricted substances need attention if the product goes into toys, packaging or consumer goods, so ask for the test data your market requires.
Plan storage and transport as part of the specification. Water-based dispersions can be damaged by freezing and by high heat inside a container, and some carriers need to be stirred or rolled before use. State the packing, such as drum or IBC size, and the shelf life from the date of manufacture, and ask for both on the label so your store staff can rotate stock correctly.
Next step
We find dispersion makers in Gujarat, match your standard, have lots tested and supervise packing. To brief a custom dispersion, book a free sourcing review.