Yves Saint Laurent All Hours Concealer, 15 ml, Concealers, Spot Treatments for Women, The Yves Saint Laurent All Hours concealer masks all blemishes and gives your skin a flawless appearance. Characteristics: has a light texture that does not emphasise wrinkles long-lasting effect How to use: Use the applicator to apply concealer to places you wish to mask. Blend in. To blend in flawlessly, use repeated circular movements with the brush.