― If I'm on honest i never really knew how to use a Skin Illuminator. But.... now i so do know how to use them, thank you 'You Tube'. ∙ These days foundations and primers some times can have skin illuminator within the product. Skin illuminators give the face a brightening effect that some times a foundation can not do alone. Skin illuminate-ers come in powder, cream, mousse, etc. L'Oréal, Me Me Me, and other brands make them - it's like make up with tiny particles that reflect light. [...].