If you buy colour for plastics, you are choosing between three formats: dry pigment powder, masterbatch, and fully compounded resin. Most processors inherit whichever one their plant started with and never revisit it — which is expensive, because the right answer changes with volume, shade count and how tight your tolerances are.
Here is how the three actually differ, and how to work out which one belongs in your plant.
The three formats
Dry pigment powder
Raw pigment, weighed and blended into natural resin at the machine. It is the cheapest option per kilogram of colouring power, and that is the whole of its appeal.
The costs sit elsewhere. Powder is airborne, so it settles on every surface in the plant and contaminates the next shade you run. Weighing is manual, so dosing accuracy depends on an operator at the end of a long shift. Dispersion depends on the screw doing work a compounder would otherwise have done under controlled conditions, so you tend to see specks, streaks and shade variation between batches. And there is an occupational hygiene exposure that most modern buyers would rather not carry.
Masterbatch
Pigment pre-dispersed into a carrier resin at high concentration, supplied as granules and metered into your natural resin at the machine, typically at low let-down.
The dispersion work has already been done, under controlled conditions, on equipment built for it. You handle granules rather than dust. Dosing is volumetric or gravimetric rather than manual. You hold one natural resin in silo and buy colour separately, which is why masterbatch dominates wherever a processor runs many shades from a common base polymer.
Compound
Resin, pigment and any additives fully mixed and pelletised into a single ready-to-run material. You load one thing into the hopper and mould.
Simplest at the machine, and the most consistent, because nothing is being mixed on your equipment. It is also the least flexible and the most capital-hungry in inventory terms: every shade is a separate SKU with its own minimum order, its own storage and its own obsolescence risk. Compounds make sense for high-volume single-shade running, and for engineering polymers where the formulation is doing structural work.
How to choose
Four questions settle it in most plants.
How many shades do you run? A processor running forty shades off one base polymer should be on masterbatch. Holding forty compounds ties up working capital in inventory that a single silo of natural resin plus forty small masterbatch SKUs would not.
What volume per shade? A shade you run continuously in tonnage quantities may justify a compound. A shade you run for two days a month almost certainly does not.
How tight is your colour tolerance? The tighter the tolerance, the further you should move away from dry pigment. Powder blended at the machine has the widest batch-to-batch variation of the three, simply because dispersion is happening on equipment that was not designed to disperse.
What is your plant like? If you run food, pharmaceutical, medical or cosmetic packaging, dry pigment powder in an open plant is a housekeeping problem you do not want to be defending during an audit.
The middle option most buyers miss
There is a fourth format, and it is the one that small and mid-sized masterbatch producers, compounders and fibre plants most often overlook: the mono concentrate, also called a single pigment concentrate or SPC.
A mono concentrate is one pigment, pre-dispersed into a carrier resin at high loading — typically 20% to 70% depending on the pigment and the carrier. It is not a finished shade. It is a building block you formulate with.
That matters if you make your own shades. You keep full formulation control and the ability to match anything, but you stop handling raw pigment powder. The dust, the cross-shade contamination, the weighing error and the operator exposure all go away, and dispersion improves because the pigment was let down under controlled conditions rather than in your extruder.
For a plant that has always bought powder because it wants formulation freedom, this is usually the change with the fastest payback — and it does not require giving up any control.
What it costs to get this wrong
The classic mistake is comparing formats on price per kilogram of the coloured material. That comparison always favours dry pigment, and it ignores everything that actually costs money:
- Rejects and regrind from specks, streaks and off-shade parts
- Changeover time lost to purging contamination between shades
- Inventory tied up in shade-specific SKUs a masterbatch strategy would not need
- Requalification when a batch drifts far enough that a customer notices
A processor rejecting two percent of output on colour defects is losing more than the entire difference between dry pigment and masterbatch.
A note on carrier resin
If you move to masterbatch or mono concentrates, the carrier matters as much as the pigment. A carrier incompatible with your base polymer will not disperse properly no matter how good the pigment is, and in engineering polymers processed at high temperature the wrong carrier can degrade in the barrel.
Match the carrier to the base polymer. Concentrates are commonly available in PE, PP, PET and PBT carriers, and engineering polymer grades are formulated specifically for the higher processing window — see engineering polymer masterbatch for what that involves.
The short version
- Many shades, one base polymer — masterbatch
- One shade, high volume, tight spec — compound
- You formulate your own shades — mono concentrates, not powder
- Dry pigment powder — only where dust, contamination and manual weighing are genuinely acceptable, which in a modern plant is rarer than most buyers assume
If you are not sure which side of those lines you fall on, the fastest way to find out is to send your base polymer, your shade count, your monthly volume per shade and your current reject rate. That is enough for a supplier to tell you whether a format change would pay for itself.
Talk to our technical team about which format suits your plant, or request a sample against your current material.