Revlon ColorStay Prep & Protect Primer Versus e.l.f. cosmetics Poreless Putty Primer

This is a silicone-based ingredient that helps create a smooth, silky, "bouncy" texture. It also acts as an emulsifier that prevents ingredients from separating in a formula.

Due to its large molecule size and water-insolubility, this ingredient is unlikely to be absorbed into skin. Irritation and sensitization tests have found reactions to silicones are considered very rare.

Glycerin (or glycerol) is a compound naturally found in your skin. It's a powerhouse humectant that pulls water into the stratum corneum.

Topically, glycerin does several things at once:

This ingredient is a powder used to improve texture, slip, and give products a silky texture.

Phenoxyethanol is a preservative that has germicide, antimicrobial, and aromatic properties. Studies show that phenoxyethanol can prevent microbial growth. By itself, it has a scent that is similar to that of a rose.

It's often used in formulations along with Caprylyl Glycol to preserve the shelf life of products.

Polymethylsilsesquioxane is a silicone used as a film forming agent.

When applied to the skin, this ingredient creates an invisible film on the surface. This film still allows oxygen to pass through, but prevents moisture from escaping. This can help condition and hydrate the skin. It also leaves a silky feel when applied.

Triethoxycaprylylsilane is a silicon-based surface modifier that makes sunscreens feel silky and makeup stay put.

Its main job is to coat mineral particles like titanium dioxide, zinc oxide, and color pigments in a thin, oily layer so they spread smoothly, don't clump, and stick to skin better.

This silicone is an emollient. Emollients create a thin film on the skin to prevent moisture from escaping.

It is not soluble in water and helps increase water-resistance in products.

Water. It's the most common cosmetic ingredient of all. You'll usually see it at the top of ingredient lists, meaning that it makes up the largest part of the product.

So why is it so popular? Water most often acts as a solvent - this means that it helps dissolve other ingredients into the formulation.

This ingredient is a combination of red, black, and yellow iron oxide pigments. This combination of colors is usually found in foundation, because it results in a "skin" color.

The EU typically uses CI numbers for colorants when applicable, such as CI 77489. In the US, iron oxides are regulated as color additives and "iron oxides" is the most commonly used name in US cosmetic practice.