Choose a primer if you are looking to smooth your skin before applying makeup. Some products contain dimethicone, a skin-smoothing silicone. A primer might also have other skincare advantages. For example, Benefit The PoreFessional ($37, 22 mL) has vitamin E, and is an oil-free formula that helps mattify the skin. Dermalogica Skinperfect Primer SPF 30 ($67, 22 mL) features pearl powder to reduce redness.