India has one of the world’s deeper pigment industries, concentrated in Gujarat and Maharashtra, and a very wide quality range inside it. If you buy coloured plastic, a pigment decision is being made somewhere in your supply chain — either by you, or by your masterbatch supplier on your behalf.
This is what that decision actually involves, and how to judge whoever is making it.
First: should you be buying pigment at all?
A real question, and the answer is usually no.
Buying pigment directly makes sense if you compound in-house, have dispersion equipment and the process knowledge to use it, and run enough volume to justify holding pigment inventory and carrying the matching responsibility.
Buying masterbatch makes sense for everyone else. The dispersion step is where most of the value and most of the risk sits, and it needs equipment and know-how that a converter rarely has a reason to own.
The common failure is buying dry pigment to save money and then dosing it at the machine. Dry pigment dosed into an injection moulder or extruder without a proper compounding step gives poor dispersion, dust and housekeeping problems, operator exposure concerns, and shade variation between shifts. We compare the options in masterbatch vs compound vs dry pigment.
If you are not set up to disperse, the pigment question is really a question about your masterbatch supplier’s pigment selection.
The properties that decide whether a pigment is right
Heat stability
Every pigment has a temperature above which it degrades, shifts shade or decomposes. The figure quoted is usually for a stated residence time — exceed either and the result changes.
This is where cheap colour matches fail. A pigment that is fine at 200 °C in a thin-wall part can shift noticeably at 280 °C in an engineering polymer. See colouring ABS, PC, nylon and POM.
Ask for: heat stability at your actual processing temperature and residence time, not a generic figure.
Lightfastness and weatherability
Two different things. Lightfastness is resistance to fading under light, usually quoted on the Blue Wool scale. Weatherability adds moisture, heat cycling and oxygen — the full outdoor condition.
A pigment can have good lightfastness indoors and fail outdoors. For anything in service outside, ask for weathering data, not lightfastness alone.
Migration and bleeding
Some organic pigments migrate — moving within the polymer, blooming to the surface, or transferring into an adjacent material. In a multi-layer part, or where a coloured component touches a light one, this becomes visible.
Ask about: migration behaviour in your polymer at your loading, particularly for reds, oranges and some yellows.
Opacity and tinting strength
Tinting strength determines how much you need, which determines cost per part rather than cost per kilogram. A pigment at half the price and two-thirds the strength is not cheaper.
Ask for: tinting strength relative to a reference, so quotes can be normalised.
Organic, inorganic, and high-performance
The three families behave differently enough that the choice usually constrains everything downstream.
| Organic | Inorganic | High-performance organic | |
| Shade | Bright, clean, saturated | Muted, earthy | Bright and clean |
| Opacity | Generally lower | Generally higher | Variable |
| Heat stability | Variable, some limited | Generally high | High |
| Lightfastness | Variable | Generally high | High |
| Cost | Low to moderate | Low to moderate | Significantly higher |
The practical consequence: a bright, clean shade that also has to survive outdoors for years and process at engineering-polymer temperatures will need high-performance pigments, and will cost accordingly. There is no cheap route to that combination, and a quote that looks cheap for it is usually a quote for something else. See organic vs inorganic pigments for plastics and high-performance pigments.
Lot-to-lot consistency is the real purchase
Pigment lots vary. Strength, shade and particle size distribution all move between batches, and that variation passes straight into your part unless somebody absorbs it.
A good masterbatch manufacturer tests incoming pigment and adjusts the formulation to hold the final shade constant. That is a large part of what you are paying them for, and it is invisible when it works.
Ask your masterbatch supplier: do you test incoming pigment lots, and do you adjust formulation to hold the match? A supplier who simply follows a fixed recipe will pass pigment variation through to you.
Regulatory status, which is pigment-specific
This is where the pigment question becomes a compliance question.
- Heavy metals — EN 71-3 sets migration limits for toys, and some traditional pigment chemistries are excluded outright
- Food contact — FSSAI and the applicable IS specifications in India; the pigment has to be permitted for the application
- RoHS — relevant where there is electrical function
- REACH — for EU export, including substances of very high concern
Some long-established, excellent-performing pigments are restricted in these applications. A supplier proposing a shade for a toy or food pack should be confirming pigment eligibility before the match, not after.
See toy safety, EN 71-3 and IS 9873 and RoHS and REACH compliance.
Dispersion is a pigment property too
Pigments differ in how hard they are to disperse. Small-particle, high-colour-strength grades generally disperse harder — the same property that makes them strong makes them want to agglomerate.
This is why pigment quality and masterbatch quality are not separable. A superb pigment, badly dispersed, performs worse than a modest pigment dispersed properly. The compounding step is where the pigment’s potential is either realised or wasted.
What to ask, depending on who you are buying from
If you are buying pigment directly:
- Heat stability at my processing temperature and residence time
- Weathering data, not just lightfastness, for outdoor parts
- Migration behaviour in my polymer at my loading
- Tinting strength against a reference
- Regulatory declarations for my end market
- Lot-to-lot variation data
If you are buying masterbatch (most readers):
- Do you test incoming pigment lots?
- Do you adjust formulation to hold the match when a lot varies?
- Was pigment eligibility for my end market confirmed before the match?
- What is the lightfastness and heat stability of this specific pigment set?
- Will you tell me if my shade and durability requirement need high-performance pigments?
Talk to us
Life Color Pigments & Masterbatches is a masterbatch manufacturer at Vasai, in the Mumbai belt, operating under ISO 9001:2015. We select the pigment set to the application — processing temperature, service environment and regulatory requirement — rather than to the lowest cost per kilogram, and we retain a physical master standard so pigment lot variation is absorbed by us rather than passed to you.
Tell us your shade or standard, your polymer and processing temperature, where the part lives and what it has to comply with, and we will tell you what pigment family that combination actually requires before anything is quoted. Related: colour masterbatches, white masterbatches, special effect masterbatches, mono concentrates, toys, automotive.
Frequently asked questions
Should I buy pigment or masterbatch for colouring plastics?
Masterbatch, unless you compound in-house with proper dispersion equipment and the process knowledge to use it. The dispersion step carries most of the value and most of the risk, and dosing dry pigment at the machine gives poor dispersion, dust problems and shade variation between shifts.
What is the difference between organic and inorganic pigments?
Organic pigments give brighter, cleaner, more saturated shades with generally lower opacity and more variable heat stability. Inorganic pigments are more opaque, more heat stable and more lightfast in a more muted palette. High-performance organics combine brightness with durability at a significant cost premium.
What is the difference between lightfastness and weatherability?
Lightfastness is resistance to fading under light alone, usually quoted on the Blue Wool scale. Weatherability adds moisture, heat cycling and oxygen. A pigment can be perfectly lightfast indoors and fail outdoors, so outdoor parts need weathering data rather than lightfastness figures.
Why does pigment heat stability matter for my process?
Every pigment degrades or shifts shade above a certain temperature for a given residence time. A pigment that is stable in a thin-wall polyolefin part can shift visibly at engineering-polymer processing temperatures, which is a common cause of a match that works in the lab and fails in production.
Do pigment batches vary?
Yes – in strength, shade and particle size distribution. A good masterbatch manufacturer tests incoming lots and adjusts the formulation to hold the final shade constant. A supplier who follows a fixed recipe passes that variation straight through to your part.
Are all pigments allowed in toys and food packaging?
No. EN 71-3 sets heavy-metal migration limits for toys and some traditional pigment chemistries are excluded outright, while food contact requires the pigment to be permitted under FSSAI and the applicable IS specification. Eligibility should be confirmed before a shade is matched.
What is pigment migration and when does it matter?
Some organic pigments move within the polymer, bloom to the surface or transfer into an adjacent material. It matters most in multi-layer parts and wherever a coloured component touches a lighter one, and it is most common in some reds, oranges and yellows.
Is a cheaper pigment always a worse one?
Not necessarily, but a cheaper pigment for the same visual shade usually means a different chemistry with lower lightfastness, lower heat stability or lower tinting strength. Lower tinting strength in particular means more is needed, so the cost per part can be higher than the cost per kilogram suggests.
Buying masterbatch for this application?
We manufacture in Vasai and supply converters across India. Tell us the polymer and the process, and we will come back with a grade and a price.