Silicone makeup base: smoothes skin imperfections; it has a light, gel consistency; provides the effect of smooth skin for many hours. Primer Base is a silicone base that creates a thin mesh on the surface of the skin that tightens and smoothes skin imperfections. The product should be used on cleansed skin, preferably after using the cream and before applying the fluid. The light gel consistency does not weigh the skin down, allowing the foundation to spread evenly and stay in place for longer.