If you want flawless eyeshadow that's going to last all day, you need to use eyeshadow primer. Eyeshadow primer is a more solid cream than face primer so that it can grab onto the pigments in the shadow and "set" the color. It will also help reduce the oils that cause shadows to crease or fade, and smooths out skin texture for a better canvas for your eyeshadow. Note that eyeshadow base is something different — these are an even stickier consistency for a more intense color pop. Choose a primer that's either sheer or close to your skin tone, so that your makeup colors aren't distorted.