Foundation, sometimes called base, is a product designed to minimize facial flaws, even out skin tone, and give your face a more polished appearance. Today's foundations are much advanced over formulas of the past. In addition to merely covering the skin, they may also feature sunscreens, nourishing vitamins and nutrients, oil-absorbers, or ingredients like alpha-hydroxy acids to diminish the look of fine lines. Foundation is available in many different formulations, including traditional liquids, cream-to-powder types, and stick foundations. Coverage may vary from sheer to heavy, depending on the product. Generally, tinted moisturizers are the lightest type, allowing more natural skin to show through. Traditional liquid foundations give more coverage, especially if applied with a dry sponge. Most brands feature different lines for different skin types, such as oily, dry, or combination skin. If your skin tends to break out, always choose an oil-free product. Once you settle on a general type, you'll need to find a color as close to your natural skin tone as possible. Test several colors by applying a stripe of each product along the side of your face. Examine the results in daylight. The one that seems to disappear on your face is the best shade for you.