MAC Studio Fix Fluid Foundation. What it is: A modern foundation that combines a natural matte finish with broad spectrum UVA/UVB SPF 15 protection. Who it's for: Anyone who wants a matte finish with medium-to-full buildable coverage. What it does: The comfortable, long-wearing formula applies, builds and blends easily and evenly while helping to minimize the appearance of pores and imperfections, giving your skin a smoother, more flawless look and finish. Foundation.