The Science of Foundation

Part I: What makes up the foundation of your well, foundation?According to James Hammer, a cosmetic chemist at Mix Solutions in Uxbridge, Massachusetts, what goes into a base will vary depending on the texture (liquid, cream, powder, mousse, etc.) and skin type it was intended for. However, there are some usual suspects that’ll most likely be in the mix:Fatty EmollientsWhile this F word doesn’t sound particularly appealing, it does wonders for your skin. According to Webster’s, emollients “have the power to soften, relax and sooth…especially the skin.” “They’re important to have in foundation because they smooth the skin and protect it from drying out,” says Hammer. On labels, look for ingredients like cetearyl alcohol (a fatty alcohols), natural and synthetic waxes (beeswax, candelilla, paraffin, carnauba, etc.), as well as fatty esters such as isodecyl neopentanoate, isopropyl palmitate and myristyl myristate.QUIZ: Get Smooth, Silky Body SkinSiliconesRecently, silicones have gotten a bad rap for suffocating pores. But according to Hammer, for every old school, heavy, pore-punishing type of silicone, there are hundreds more have very beneficial effects. For example, if you’re acne-prone, you’ll definitely want ‘dimethicone cross polymer’ on your label. Not only does it not linger in pores, it makes them appear smaller.

Silicones offer other skin-saving solutions, too. “Silicones are used to improve application properties—as in make it easier to blend and smooth on—and for giving a product water resistance,” says Hammer. (Translation: If you’re a sweater, this one’s for you.) “They also provide a variety of effects, from a silky feel, to diffusing the appearance of fine lines,” he says.PreservativesYou know when you leave a lemon lingering in your fruit jar too long and eventually it gets moldy and gross? That’s exactly what these bad boys prevent from happening to your foundation—they stop the growth of bacteria. Since liquid foundation contains water, they’re more susceptible to bacteria than powder formulas, and should be replaced every six to twelve months. If you’re a powder fan, go for ones with natural minerals—they don’t require preservatives, because they’re H2O-free (no threat of bacteria!).A surefire way to prevent bacteria cropping up in your foundation? As soon as you rip it open, use a Sharpie to scribble the month and year on the bottom of the bottle so you know when it expires (like you would with a batch of homemade pasta sauce pre-freeze). And don’t assume that because your formula has separated, that it’s contaminated. “That’s just the oil and water moving apart,” says Hammer. “It doesn’t mean it’s gone bad and that there’s bacteria. Simply shake the product before use.”

 Pigments“Foundation relies heavily upon iron oxide pigments to give natural-looking skin color shades,” says Hammer. Titanium dioxide and zinc oxide (aka the skin-protecting powerhouses in your SPF) are used as the white base pigment. The skintone colors come from iron oxide, a mineral that comes in yellow, red, brown and black. “These shades are blended together with white to create just about any natural skintone you can imagine,” says Hammer.Cream foundations have the biggest dose of pigments. “These have a thicker emulsion, which carry a high amount of pigment and therefore give more coverage,” he explains. While sticks often seem daunting, L.A. makeup artist and YouBeauty Makeup Expert Emily Kate Warren says they’re fab for hiding isolated imperfections. “When you need concentrated coverage in one area—for example, if you have redness around your nose or any other veiny areas—all you’ll need is a quick swipe of a stick,” says Warren, who recommends Bobbi Brown Foundation Sticks.Part II: Find the right foundation for your skin typeThe best foundations don’t just cover up complexion concerns—they actually make your skin healthier, too! Here’s how to know which formula’s right for you.If you’re…battling breakoutsYou could go either way here: liquid or powder (as long as it’s oil-free). Your skin already has an issue getting rid of its natural sebum—or its production is on overdrive—so it definitely doesn’t need any extra! “Liquid foundation often contains a lot of oils or emollients,” says Hammer. “Also, if water is low on the ingredient list, it’s probably an oily formula.” Warren suggests looking for something that touts being hypoallergenic. “When you have recurring pimples and the skin is inflamed, eliminating ingredients that will irritate them further helps them heal faster,” she says.QUIZ: Are You Happy With Your Face?If you’re…worrying about 24/7 shine“Use dry powder and mineral-based products,” says Hammer. “These help absorb oils that sit on the skin’s surface.” If you’re blemish-prone, Warren suggests using mineral powder foundations (check labels for cornstarch, kaolin and clay) like GloMinerals Pressed Base. “You can get good coverage and a shade perfect for your skintone,” she says. And since it absorbs shine, you won’t need another layer of powder on top to “set” the shade—it’s an all-in-one. “Just keep reapplying throughout the day as needed to get rid of shine,” she explains.If you’re…waging the war on wrinklesA liquid, cream or mousse-type formula like Cover Girl Foundation your best bet as they are richer, more luxe textures likely to contain wrinkle-plumping moisturizers that smooth out the skin’s surface. Also try test-driving the popular fine-line diffuser nylon 12—it’s like Spanx for your skin. “It’s a tiny round microsphere that sits on the skin and softens the appearance of lines,” says Hammer.MORE: How to Wear Makeup When You Exercise