Foundations provide the perfect base for the application of the rest of your make up. Cosmetic foundations such as powders and liquid foundation are used to create a clear, smooth skin tone-the illusion of seemingly flawless skin texture that will last as long as you desire. Foundations provide the perfect base for the application of the rest of your make up. Foundations may be water-based, oil-based or oil-free, with varied consistencies and coverage, and are available in liquid, cream or powder form.