I use MAC Matte as a primer!
and I cant say enough about it. I use it overtop of prep and prime skin (not the SPF 50 one).
I either place it in areas where I have little acne bumps, to even them out, or if I'm looking for an allover matte base I will put it everywhere.
Liquid and powder foundation apply like a dream on top of this stuff.
The Matte basically smoothes out imperfections in your skin and fills large pores so that the foundation goes on much smoother.
I am a huge fan, I cant say enough about it. It reminds me a lot of Bare Essentials face primer, if anyones tried that?
Any ways, definitely invest in it
A little bit goes a long way with this stuff too! But personally Id use it on top of a moisturizer or a light primer like MACS prep and prime skin.
Hope that was helpful!