All-in-1 foundation & concealer Flawless finish for all. The Blunder Cover is a multifunctional foundation that doubles as a make-up base and concealer. It offers unique coverage with a natural, radiant and even finish. The darker shades can also be used to contour and sculpt the face. Application: Apply the product as a foundation on the entire face or as a concealer on selected areas. Work the product gently into the skin with a brush or your fingers.