If you want your foundation to stay in place for as long as possible, then a good primer is non-negotiable. “The primary purpose of a primer is to prepare the skin for foundation,” explains make-up artist Joy Adenuga. “Depending on your skin type, this could be blurring the skin, filling in open pores, reducing shine, providing hydration, or providing a smooth canvas for make-up.” As well as keeping your foundation firmly in place, the best primers do much more besides. Whatever your requirements, whether it’s mattifying an oily T-zone, blurring uneven texture and fine lines, obscuring the appearance of pores, or hydrating irritated skin, the best primer can handle it all.