New IngredientsFor a lot of us, the idea of age-erasing foundation sounds like a fairy tale, and we mean "The Emperor’s New Clothes." It’s one thing for a little paint and spackle to cover blotches and blemishes, but when a foundation claims to tighten, brighten, and firm over-forty skin — well, we can only say we weren’t born yesterday.Then again, neither were cosmetics company executives, who know a market need when they see one. Today’s foundations really are better and smarter than those of just a few years ago — and now, that little jar of beige may be our fastest route to younger-looking skin.As we got older, a strange thing happened: We stopped wearing foundation, or started using tinted moisturizer or (for the laziest among us) self-tanner as a do-all base. We didn’t want anything on our faces that would collect in our laugh lines or emphasize our imperfections.Cosmetic companies, predictably, wanted us back — badly enough to go back to the drawing board and reinvent foundation as a bona fide skin treatment. In 2006, the facelift in a bottle — a running gag in the beauty industry for years — has become a reality.Just read the labels: High-powered humectants, antioxidants, minerals, and botanicals get priority listing.Revlon’s Age Defying Foundation with Botafirm ($14) claims its hexapeptide reduces wrinkles by 50 percent in two weeks. Both Maybelline New York Instant Age Rewind ($8) and Lancome Renergie Lift Makeup ($36) contain caffeine for a tightening effect. DiorSkin Sculpt Foundation ($28) has the peptide Matrixyl to stimulate collagen production.There’s no denying that today’s foundations offer a more natural look. The shades have perfect pitch, and the cocktail of light reflectors, emollients, and humectants really does make dehydrated skin look dewier. Creating these products wasn’t a walk in the park. "Makeup that wears well on mature skin is a challenge," says Anne Carullo, vice president of corporate product innovation for Estee Lauder. "The topography of the face is so different, with visible textural changes and things you don’t see, like oils in the skin that can cause makeup to change color. Until now, it’s been difficult to combine a high level of treatment with color and keep the formula from breaking down. But with new emulsifying systems, we’re able to fuse materials that have not been stable together before."But do these high-tech foundations really work as skin treatments? Well, yes — to a degree. "Let’s just say I’m not worried about my Botox business drying up," says Deborah S. Sarnoff, MD, associate clinical professor of dermatology at New York University School of Medicine. "While the inclusion of antioxidants, vitamins, and peptides can only help aging skin, no topical ingredient can give you the dramatic effect of injections that freeze a muscle or fill a wrinkle." Still, why not use a product that gives you coverage and treatment in one package? As Sarnoff says, "It’s killing two birds with one stone." Here are some other new foundations we’ve tried and loved.The Best FoundationsFor Serious CoverageWhat do you do when you need to cover redness, brown spots, and occasional blemishes but want to keep it between you and your magnifying mirror? Cream foundations (stop wincing — we mean it!) mimic great skin while providing the kind of coverage that used to require layers of base, concealer, and powder.Estee Lauder Re-Nutriv Intensive Lifting Makeup ($65) Contains whey proteins and humectants that temporarily add a plastic-wrap tautness and fill out wrinkle — -perfect for skin that’s dry, delicate, or noticeably loose around the mouth and jawline. When we tried it, the color stayed true all day and evening, with no touch-ups necessary.La Mer The Treatment Creme Foundation SPF 15 ($85) Contains the same marine botanicals as the legendary face cream (including the anti-sag star-blue algae), and we loved the way it airbrushed large pores and discolorations around the nose and chin. It also refused to puddle in non-Botoxed grooves, even after two hours of grimacing and grinning at a business lunch.La Prairie Cellular Radiance Lifting Foundation ($225) Don’t cringe at the price: A tiny dab of this oil-in-water souffle goes a long way, and the silicone formula blends to a second-skin finish, making light of sun spots and spider veins.