Related

Class	Doing what	Names on the label
Pigment	The colour and the coverage	Titanium dioxide, iron oxides (CI 77491/77492/77499), zinc oxide
Vehicle	Carries and spreads the pigment	Water, cyclopentasiloxane, dimethicone, esters
Film former	Makes it stay	Trimethylsiloxysilicate, acrylates copolymers
Dispersing agent	Stops pigment clumping	Surface-treated pigments, polyhydroxystearic acid
Fillers	Slip, blur, oil control	Silica, mica, nylon-12, starch
Emulsifier	Holds water and oil together	PEG-10 dimethicone, cetearyl alcohol
Preservative	For anything containing water	Phenoxyethanol, caprylyl glycol

Titanium dioxide and iron oxides do nearly all the work. Four pigments — white titanium dioxide plus red, yellow and black iron oxides — generate essentially every foundation shade on the market. The industry's shade-range failures were never a pigment problem.

Two independent variables:

• Depth — how light or dark. Easy to judge, easy to get wrong under shop lighting.
• Undertone — the underlying cast: cool (pink, red, blue), warm (yellow, golden, peach), neutral, or olive (a green-grey cast that is genuinely distinct and was ignored by mainstream shade systems for decades).

Match along the jawline in daylight, not on the wrist or the back of the hand, and check it after ten minutes because many foundations oxidise — the shade shifts darker or more orange as the vehicle evaporates and the film sets against sebum. A shade that matched at the counter and looked wrong an hour later oxidised.

Coverage — sheer, medium, full — is a function of pigment load and opacity. Finish — matte, natural, satin, dewy — is a function of fillers and the light-scattering behaviour of the film. They vary independently: a full-coverage dewy foundation and a sheer matte one both exist.

Formats: liquid (the default), cream and stick (higher coverage, portable), cushion (sponge-loaded compact, sheer, easily reapplied), powder (see Face Powder), and serum-foundation hybrids.

For most of the category's history the standard range ran roughly a dozen shades clustered in the light-to-medium band, with token deep shades that were frequently too red or too grey. The commercial demonstration that broad ranges sell — a 40-shade launch in 2017 and the industry-wide expansion that followed — changed the shelf materially and is the clearest example in modern cosmetics of a market failure being corrected by competition rather than by regulation.

The remaining gaps are at the extremes of depth, in olive undertones, and in non-flagship brands.

Cosmetic in the US — FDA primary category (08), makeup preparations (not eye). The binding constraint is colour additives: only additives FDA has approved for the intended use may be used, and certified colours must come from FDA-certified batches. This is the one part of US cosmetic law with genuine premarket control.

Foundation with an SPF is also an OTC drug: sunscreen monograph, Drug Facts panel, expiration date, and the Broad Spectrum test before that term may be used. The dose caveat is severe here — nobody applies foundation at 2 mg/cm², so a labelled SPF 20 foundation delivers a fraction of that in practice.

Carmine (CI 75470) must be declared by name in the US, because of documented hypersensitivity; it is also the ingredient that makes a product non-vegan.

Twelve months after opening for a pump; six to twelve for a cushion or a pot, where the applicator returns to the product every use. Wash sponges and brushes — they are the actual contamination route. Separation is normal in some formulas and shaking fixes it; a smell change, a colour change, or a texture that has gone lumpy is the end.

• Makeup — the shelf this sits on, and the rest of it.
• Cosmetics — what the label is legally allowed to say, and the full catalogue.
• The rest of Face — Face Primer · BB Cream · CC Cream · Tinted Moisturiser · Concealer · Colour Corrector · Face Powder · Setting Powder · Setting Spray.
• Regulatory statements here follow the FDA and EU sources listed on Cosmetics, read 16 August 2026.