As part of a new S! TV series, we'll be finding out the answers to some of our viewers' most pressing beauty questions, with the help of make-up artist Stephan Ulvund Øien from IsaDora Global. 

First up this week, Stephan gives us some expert insights into using primer to mattify, brighten, highlight, and, most importantly, prime your face for foundation so it stays in place all day long.

Any make-up artist will tell you that primer should be a key part of your cosmetics arsenal, but so many of us don't use one. We bet Stephan will change your mind…