Question 1

How should powder colourants be dosed in soap and cosmetics?

Accepted Answer

As a guide, 0.1 – 2.0 % for soaps and 0.05 – 1.0 % for make-up and powders, depending on the intensity you want. The pigments are concentrated, so add them gradually and keep checking the colour as you go.

Question 2

How do I prepare a pigment so that it does not clump in the mass?

Accepted Answer

Disperse it in a small part of the oil in oil-based systems, or in glycerine or propylene glycol in gel and glycerine bases. Sifting it and mixing it gradually into the base helps too.

Question 3

Do powder pigments stain the lather or the skin?

Accepted Answer

No – they are insoluble, so with correct dosing and even dispersion they typically stain neither the lather nor the skin. At an excessive dose, however, sediment or a coloured “stain” when wiping can occur.

Question 4

Which powder colourants are suitable for cold process soap?

Accepted Answer

Above all iron oxides, green chromium oxide and ultramarines – they stand out for their stability to heat and alkali; violet manganese loses its colour in an alkaline environment. Mica is used in CP soap for pearlescent effects and swirls, but shades with organic coatings may change colour in an alkaline environment – oxide coatings are stable. Choose a conservative dose and judge the final colour only once the soap has set.

Question 5

When are liquid colourants the better choice?

Accepted Answer

In water-based gel systems and glycerine soaps – they colour the mass quickly and evenly without the powder dispersion that powder pigments require.

POWDER DYES