Laura Mercier's foundation primer is a lightweight and smooth gel/cream meant to be used before applying your foundation. The primer creates an invisible layer that fills in all imperfections and smooths out skin, so when you apply your foundation, it will look more smooth and flawless. I personally notice a pretty big difference in the outcome of my makeup when I use the primer versus not using it. The original - was created by Laura Mercier in 1995. This primer is perfect and ideal for normal and combination skin. Not only does the primer improve the look of your makeup, but it is also good for your skin. The primer contains vitamins A, C, and E which act as antioxidants and protect the skin from harmful, aging effects of the environment and everyday life. I did like this primer, but I will never purchase it again. I think the price is absolutely crazy for a product that is only "good/average". Another down side of this primer is the smell of it. I think it smells bad, but a friend of mine who also used it did't mind the smell so much.