How much pigment is enough for colour, and what goes wrong at high loading?

There is no general number — it depends on the pigment's strength, the base colour and the target depth. Typically 0.5–10%, higher for deep shades.

Strength varies widely. Organic lakes are strong, so 1–3% gives clear colour. Inorganic pigments such as the iron oxides are weak and often need 5–10%. A white base containing TiO2 dilutes everything and pushes the number up; a transparent base reads more directly.

Overshooting costs three things. Skin feel degrades, because pigment absorbs oil, so the formula turns dry and draggy. Pressed strength falls, because pigment particles do not bond to the platelet fillers as well. And cost rises, especially with lakes.

There is a quieter problem: at high loading with poor dispersion, the surplus floats and you get speckling and rub-off on top of the wear problem.

Sample three levels — 1%, 3%, 6% — read L/a/b, and take the lowest point that hits the target depth. Do not fix it by eye in a single pass.