Colour & Dispersion FAQ

By the shade you need and by the regulatory route you can accept, not by preference.

Inorganic pigments (iron oxides, ultramarine, chromium oxide) are mineral, opaque, light-stable and cheap per unit of colour. They cover the earth tones and the whites, and they are the default in foundation and blush. Organic lakes (D&C and FD&C type) give the bright reds, yellows and blues that inorganics cannot reach, but they are dyes laid on a substrate, so they are less opaque, less light-stable, and their permitted use varies more between markets.

Our range splits exactly along that line: iron oxides and ultramarine under Inorganic, the lake series under Organic. If a shade can be hit with an inorganic, hit it with an inorganic.

Slurry if you are under roughly 200 kg per batch or you do not have a bead mill; dry pigment if you are large enough to amortise the equipment and the cleaning.

The slurry saves you the milling step, the dust, and the batch-to-batch variation that comes from inconsistent milling. The trade-off is that you are committed to the carrier and the pigment content the supplier chose, and you pay for the carrier weight. Above a certain volume, milling your own becomes cheaper per kilo of colour.

The other consideration is colour control: with a slurry, the colour of the batch is set before it reaches you, which is a real advantage in a shade-critical product.

The continuous phase of your finished emulsion, and nothing else. Put a water-based slurry into an anhydrous base and it will not incorporate; put an oil-based one into a gel and the same thing happens.

Beyond that: water-based slurries suit cushion foundation, liquid foundation, gel liner, nail polish and any aqueous system, and they give a lighter, less greasy feel. Oil-based slurries suit lipstick, lip gloss and anhydrous systems, and they give better wear and water resistance.

If you make both, you need both, and the pigment content differs — water-based runs lower, at 20–65%, because a water carrier with a high pigment load becomes unstable.

They are encapsulation-based colour-change systems. The colour shift is triggered by the aqueous environment around the particle, which in a cosmetic product means pH and moisture rather than temperature.

The particle is a shell containing a colourant system that responds when the surrounding medium changes. That is why the application route matters so much: on dry skin with no water present, nothing happens; when the product is rubbed onto skin or mixed with a water-based phase, the shell environment changes and the colour shifts.

This is why the two series exist. It is not a temperature indicator and should not be specified as one.

The CI number is the Colour Index identifier for the colorant itself, independent of who makes it or what it is called commercially. Regulators list colorants by CI number.

That means your registration and your customer's questionnaire are about CI 77492, not about Kingpigment 340Y. Two things follow. First, when you switch supplier or grade, the CI number is what has to stay constant. Second, when you check a market's permitted list, you check it by CI number — and the same CI number can be permitted in one product category and restricted in another in the same market.

Every grade in our tables carries its CI number for that reason. If a technical document you receive does not, ask for it.

Choose by the pigment, not by a preference for higher concentration.

High loadings are achievable with dense, well-behaved pigments: TiO2 at 73% (867W), black iron oxide at 70% (926B), and the treated versions at 65%. Organic lakes sit lower — 40% for Red 7 (190R), 50–55% for most of the Red series — because a lake's low density and high oil demand make a higher loading unpourable.

So the number tells you what is inside, not how good the product is. A 40% lake slurry and a 73% TiO2 slurry are both fully dispersed; they are simply different pigments.

Because water has a lower viscosity at the same solids and cannot hold a dense pigment load in suspension without settling or gelling.

The numbers show it: TiO2 in water reaches 60–65% (848W, 851W) because it is dense and disperses well, while the transparent iron oxides sit at 30% (610R, 630Y) and organic lakes at 20–30% because they are light and highly absorbing. The same pigment that runs at 73% in oil runs at 60% in water.

That is a physics limit, not a formulation choice. If you need a higher delivered colour, you use more slurry rather than a more concentrated one.

460 is the universal grade and 160 is specified for W/O emulsions.

The 460 series (WY-460, WR-460, WB-460, BS-460, WG-460, WV-460) covers six colour shifts including white-to-skin-tone, and is used across emulsion types. The 160 series (WB-160, WY-160, WR-160, WBr-160, WG-160, BS-160, WV-160) is designed for water-in-oil systems, where the continuous oil phase and the internal water phase create the specific environment the particle needs.

Choosing the wrong series is the most common failure: a 460 grade in a system it does not suit simply does not shift, and it looks like a dead batch.

Below roughly pH 5 it starts to decompose, releasing hydrogen sulphide; the change is visible as a loss of blue and a smell.

That matters in three places: an AHA or BHA product, a low-pH gel, and any emulsion where the water phase drifts acidic over shelf life. In a normal cream at pH 5.5–7 there is no issue in practice, which is why ultramarine is so widely used.

If your formula is acidic, either buffer it or move to a blue that is not ultramarine — an organic lake, or a blend of iron blue where the market permits it.

It makes the pigment surface lipophilic so the dispersion stays stable in the oil phase and the film wears longer.

DSG — disodium stearoyl glutamate — is a surface treatment applied to the pigment before dispersion. In practice it reduces viscosity at the same pigment load, improves the water resistance of the finished film, and makes the slurry easier to incorporate into a W/O or anhydrous base. The treated versions carry a lower pigment content (50–65% instead of 60–73%) because the treatment adds weight.

Use it when the finished product needs wear or water resistance. Skip it when it does not — you are paying for a treatment you will not see.

Particle size. Transparent grades are far finer, so they absorb colour but scatter much less light — they tint without hiding.

Regular iron oxide at a few hundred nanometres gives opacity and coverage: it is what you use when you want to hide the skin. Transparent iron oxide (our 610R and 630Y) is small enough that it no longer scatters visible light efficiently, so it behaves almost like a dye — warm, transparent, and useful for adjusting undertone without changing coverage.

That makes transparent grades the tool for shade correction in a translucent formula, and regular grades the tool for coverage.

Usually because the particle is fully wetted and stays wetted, so there is no change in its local environment to trigger the shift.

The effect depends on the particle experiencing a change — typically moisture or pH — when the product is applied. In a heavily wetting base, or one where the water activity is already high and constant, the particle is at equilibrium from the moment it is mixed in and there is nothing left to trigger.

Check three things in this order: is the series right for the emulsion type; is the base wetting the particle too early; and is the loading high enough to be visible. The third is the most common and the easiest to fix.

It changes packing, coverage and how the pigment disperses — and in a pressed product, it changes the press behaviour too.

340Y yellow and 116R red are needle-shaped, which gives good colour strength and a slightly directional light response; 920B black is spherical, which packs densely and gives a smoother, more uniform black; 410G chromium oxide green is rhombus, which presses well and is the most dimensionally stable of the three.

For most formulas the shape is a secondary consideration behind the CI number and the colour strength. It becomes primary when you are fighting either dispersion (spherical is easiest) or press hardness (rhombus packs most densely).

It is a set of four dispersions built for transfer-resistant foundations, where the film has to stay put on oily skin for a full day.

The four grades are TiO2 (869W, 60%), red iron oxide (116R, 55%), yellow iron oxide (340Y, 50%) and black iron oxide (920B, 50%) — that is, a complete foundation shade-building set. They are treated for compatibility with the film formers used in long-wear systems, so the pigment does not migrate into the oil phase and destabilise the film.

Using all four from the same series keeps the treatment consistent across the shade, which is what stops a deep shade from wearing differently from a light one.

Accept soft settling, prevent hard caking, and mix before use.

A water-based dispersion with a high pigment load will settle; what you control is whether it settles into a soft sediment or a hard cake. Storage temperature between 15 and 30 °C, no freeze-thaw, and no long exposure to direct light covers most of it. If the sediment is soft, rolling the drum restores it.

For a formulation where settling in the finished product is a problem, a rheology modifier in your own base does more than any change to the slurry.