Primer is divisive. There are those who swear by it — and have the Instagram-ready skin to prove it — and those who think the stuff is a pore-clogging, breakout-causing nightmare. To be honest, we’re not entirely sure where we stand. As with all products, there are some amazing priming bases out there, but we’ve also fallen victim to heavy, sticky, flaky formulas. So we asked the skin pros: Could this makeup step be doing more harm than good?