THIS. FOUNDATION. Omg. I have really tricky skin for foundation, quite oily and acne prone, so difficult to find something that (a) stays on and (b) has good coverage. I discovered Mac Studio Fix Fluid and fell in love, used that for a few years. But their policy on animal testing in China just kept bugging me, so I gave this Studio Skin a try (as from 2017, Smashbox doesn't test on animals). AAAHHH. I love it so much. It is so beautifully spreadable and buildable, has such amazing coverage I hardly ever wear concealor, and really does stay on for 15 hours. The price is PAINFUL, but compared to other foundations in its class, it's pretty comparable. It also lasts for up to 3 months because you don't have to reapply every 6 hours, so #worthit.