How we test eyeshadow primers at Glamour:Georgia Trodd, Glamour's Senior Commerce Writer, testing the Milk Makeup Hydro Grip Eye Primer. We've been testing makeup products – from the best mascara to cream blushers – for over five years at Glamour. Eyeshadow primers should sweep across the eyelids easily, without pulling your skin or causing any irritation. Eyeshadow primer should ensure your shadow looks just as it does upon eyeshadow application, hours later. While I don't wear eyeshadow every day, an eyeshadow primer is one thing I never skip when I do.