By imparting moisture to the skin cells on the outermost layer of the skin. It also forms a thin barrier which traps moisture underneath, thereby preventing the evaporation of water from the skin's surface. Creams also accelerate the hydration of skin cells on the outer layer, giving the skin a temporarily smooth, plump appearance. Exfoliants improve the appearance of the skin by sloughing away flaky skin, blackheads and some dead skin cells. Astringents improve skin tone and texture by swelling the pore walls so dirt and debris.