Since they ultimately serve different purposes and have different textures, you can use an eyeshadow primer and an eyeshadow base together. It’s important to use them in the correct order, though. Primer usually has a thinner texture and is designed to keep the oils in your eyelids from breaking down your eyeshadow, so it should be applied first. You can then layer a tinted or colored base over the primer to help it stay in place all day.However, you don’t have to use eyeshadow primer and base together. You can wear the primer under your eyeshadow without a base to help improve its wear time, or you can opt to apply an eyeshadow base and layer eyeshadow over it to intensify the color.