Many foundations, pressed powders, and loose powders offer a refined, smooth, and lightweight sensation upon application—a quality often attributed to a class of ingredients known as "organosilicone elastomer microspheres." IOTA 9613, for instance—identified by the INCI name "Vinyl Dimethicone/Methicone Silsesquioxane Crosspolymer"—is a type of crosslinked organosilicone elastomer. Typically appearing as a white powder with a particle size of approximately 6–13 μm, it imparts a delicate texture; when incorporated into a formula, it enhances the product's slip and spreadability during application.
In the realm of color cosmetics, these microspheres are frequently used in liquid foundations, pressed powders, loose powders, eyeshadows, and blushes. They facilitate a more uniform distribution of pigments and powders across the skin, minimizing a "heavy" or "cakey" appearance and resulting in a more natural-looking finish. In some formulations, their ability to carry powders and modulate skin feel is leveraged to create a smoother, silkier texture after the makeup has set. When used in skincare creams or sunscreens, they also help refine the texture of the product, making the application process feel lighter and more effortless.
From a formulation perspective, these ingredients are not merely "fillers," but rather "sensory modifiers." The concentration used varies by product type: for example, pressed powders typically contain 5%–10% (with high-end versions reaching 20%–30%), while lip glazes and lipsticks generally contain 3%–8%, and liquid foundations around 5%–10%. The exact dosage should always be determined through testing and adjustment, based on the specific formulation system, the ratio of other powders, and the desired sensory profile.