Saturday, May 5, 2012
The Science Behind Long-wearing Lip Color
We all want our lip color to stay put from application to removal, but there’s always a compromise: A hydrating payoff that’s gone after a few hours, or in the case of long-wearing lip color—an ultra-dry pout. Products designed for heavy-duty lip wear come in multiple water- and polymer-based delivery systems, but the drying effects are nonetheless felt after a couple of hours. “Water-based formulas use water-soluble dyes to stain the lips, while two-step products—a base color with a clear top coat—use polymer films to fix and seal the color,” explains cosmetic chemist Nick Morante. Unfortunately, these films have the tendency to harden and stiffen on your lips after awhile. The concept of a day-to-evening lip color has been around for almost a century, but why do so many formulas continue to dry out lips?
“Some ingredients in long-wearing lipsticks are hygroscopic, meaning they attract and absorb water or moisture,” explains Nick. “While this attribute is desirable to maintain hydration in the product, an ingredient can over-absorb moisture from the lips if it’s too hygroscopic.” What actually happens on your pucker? The coating of product creates an occlusive film which traps moisture in, much like Vaseline, but doesn’t allow any moisture to enter—called transepidermal water loss. “High levels of the actual staining pigments tend to dry out lips as well,” reveals Nick. “Over time, lips may feel dryer with a high pigment load on the lips, so it’s wise to alternate with sheer or low-pigment products to help retain moisture.”
Realistically, technology hasn’t created a truly long-lasting lip color that everyone will love. But if you’re searching for a comfortable formula for a special occasion, look for lip products (either in solid stick or liquid form) which contain silicas and silicone polymers or Acrylates Copolymers—”usually lengthy names with ‘-sil’ somewhere in them,” adds Nick. From a color standpoint, look for pigments such as Red 22, Red 28, and Orange 5, which actually stain the lips in varying shades of red or pink. “The color stays long after the actual lip product has worn off because of the slightly acidic pH of lip moisture.”