For starters, it took celebrity makeup pro Charlotte Tilbury years to develop.
"Backstage at the Victoria's Secret Fashion Show, when I used to do those girls with amazing bodies, they wanted to highlight their limbs, so they would look leaner and longer and more shimmery and desirable. There would be a whole palaver of powders and creams to make this happen," she explains. "I wanted a product that would give you that longer, leaner celebrity limb. It's that Brazilian skin. If you have any freckles or age spots, it smooths everything out."
And in case you needed further convincing to try this out, Tilbury calls it her "slimmer shimmer" and describes it as Spanx for the skin.