Early pigments for watercolour or oils were mostly made by grinding
coloured minerals to a fine powder and then mixing with a binder.
Some of the best and brightest colours were either very expensive such
as powdered lapis lazuli or very poisonous like mercury or arsenic minerals.
Many cheap or common minerals produce dull "earthy" coloured paint.
As chemistry developed coloured dyes were produced. Most dyes on there
own produce a paint that is transparent ( more like an ink. )
By using a white base like barytes or witherite then adding coloured
dye very bright paints can be created which will cover well.
Modern alternatives used now are calcium carbonate ( Chalk ) which is
cheap or titanium dioxide for its whiteness.
|