Click! You and your friends eagerly gather around the camera to see the group shot you took. It's been a great evening together, and you're happy to capture the moment. But wait, why is your face so shiny? It's not the healthy, dewy look like everyone else has; your face looks like an oil slick hit it. Even though you use powder and other oil-control products, you can't seem to get rid of your skin's oily appearance, and you've got a camera full of pictures to prove it.
This condition is not out of the ordinary. If you're one of the many people afflicted by oily or combination skin, you may have a tough time combating the oil so that it doesn't become the prominent feature on your face. This oil is called sebum, a substance produced by the sebaceous glands, and its main function is to lubricate the skin and hair. Oily skin is a result of an overproduction of sebum caused by any number of factors, including hormones, bacteria, medications and heredity [source: Mayo Clinic]. Oily skin can occur all over your face, or along what's often referred to as the "t-zone," a t-shaped area that runs across the forehead and down the nose and chin.
Acne medication and special facial washes can help fight oily skin, but sometimes the sebaceous glands are so active that within a couple hours of washing, your face might have excessive oil on it again. To fight oily skin throughout the day, a mattifier can help control sebum without you needing a prescription from a dermatologist. One such mattifier is a mattifying lotion, a product with distinct ingredients that's formulated to soak up sebum. When you apply the lotion on your face, it works to absorb the oils and give skin an overall matte appearance.
What beneficial properties do these lotions have, and how do they control skin oils so effectively? On the next page we'll get into the chemistry behind the lotion.
Chemistry Behind Mattifying Lotions
Before we get into how lotions have mattifying properties that fight oil, let's first look at the chemical makeup of lotions themselves. A basic lotion is typically a semi-solid emulsion; that is, it's a combination of two liquids that can't usually be put together, such as oil and water. In order to combine them, one is added to the other in droplet form. Other ingredients such as emulsifying agents and stabilizing agents are added to the substance to help it form and keep it together [source: Personal Care Products Council].
To create a lotion that controls sebum and gives the skin a mattified appearance, the product must also contain an absorbent, an ingredient that can soak up other liquids. One typical absorbent is talc, a powdered hydrous magnesium silicate. This is a clay-like substance that contains silicon, oxygen and at least one metal, and it acts as an absorbent to soak up excess water or oil on the skin. Talc is an ingredient in many color cosmetics, as it helps control shine, yet is a soft substance for the skin. Some mattifying lotions use these clay-based silicates as a key ingredient in how they control sebum.
Other mattifying lotions may contain polymers, or plastics, to help aid in sebum absorption. A polymer is a chemical compound made up of repeating structural units, and they come in a variety of structures. Silicone polymers, which have been used for decades in skin care products, add emollient, or moisturizing, factors to make the products more soothing to the skin. Silicone also helps reduce levels of stickiness and foaming within the product.
Dimethicone is one of the more common silicone polymers, and its repeating chemical unit is shaped in a linear structure. This ingredient is important for a lotion's consistency, and when it dries, it provides a protective layer or film on the skin that acts as a barrier to unwanted substances [source: WebMD].
Although silicone polymers are still used as a significant ingredient in many mattifying lotions, the development of silicone elastomers furthered the chemical capabilities of sebum-controlling products. On the next page, we'll look at how silicone elastomers transformed the oil-control industry.
Silicone Elastomers Advance the Industry
As we discussed on the previous page, silicone polymers such as dimethicone help create protective barriers on the skin. In the 1980s, researchers discovered how to create elastomers for the skin care industry. In terms of sebum control, this discovery added the mattifying component consumers desired because the silicone elastomers absorb multiple types of oil and give the skin a smooth, powdery feel.
Elastomers are formed when a catalyst activates a cross-linker, or a reactive chemical, creating connections between linear polymers. When you look at a linear polymer, it can have reactive sites along the chain. Cross-linkers connect linear polymers and create a new substance -- the elastomer -- with both a different physical and chemical makeup. The difference between the linear polymers and the elastomers is that, when solvents are introduced as ingredients in the product, linear polymers become soluble, whereas elastomers swell or expand.
The amount a silicone elastomer can expand depends on the number of cross-links. Fewer cross-links create a softer product with great expanding capabilities. More cross-links produce a harder product that doesn't expand as much when in the presence of a solvent. The more the elastomer expands, the more of a smooth and powdery feeling it should give your skin. This is why silicone elastomers -- moreso than silicone polymers -- work well as mattifying agents to give your skin a smooth, even appearance that makes a good base for applying makeup.
Also, when a substance called cyclopentasiloxane is included in the silicone elastomer, it helps to dissolve sebum and also to improve activity between the sebum and the elastomer, which can make the mattifying effect last longer [source: Starch].
Now that you know a little more about the chemistry behind the product, let's look at the different types of mattifying products on the market.
Typical Mattifying Products
The wide variety of options allows consumers to pick the product best suited for them. You typically apply these products before putting on the rest of your makeup, but many of them can be reapplied over makeup throughout the day without having any detrimental effects.
As we described earlier, talc and powders are popular products for oil absorption.
Cream-based mattifying foundations help control oil while creating a smooth, consistent skin tone. Certain lines of mattifying foundations are designed specifically for stage and screen use, as they prevent shine from appearing even under hot stage lights.
Mattifying lotions are common, but they do vary in their consistency. Some are smooth, like an average lotion, and as you rub them into your skin, they absorb the excess oil. Lotions with a large amount of silicone initially feel like a clump of gel-like globules, but as you rub the lotion into your skin, these globules dissipate and the skin absorbs them. Some lotions come with added color, to use as a foundation replacement.
Balm and gel mattifiers can feel less weighty than either lotions or powders, and they can be reapplied as needed during the day. Some recommend using special sponges or brushes for application, but sometimes you can apply these just as easily with your fingertips.
Sprays and mists allow you to add a mattifier without having to rub a product into your skin. They can also feel refreshing, particularly after exercising.
Oil absorbing sheets are small sheets of rice paper that you blot oil with. These are especially good for midday touch-ups. These delicate pieces of disposable paper are more suited for slightly oily skin or times when the sebum is just starting to appear on the skin. If the oil is more prominent, just one sheet of rice paper may not be able to fully absorb it.
Many of the ingredients in mattifiers have been deemed safe for use. If dimethicone is an ingredient in a mattifier, it should be no more than 24 percent of the product [source: Cosmetic Ingredient Review]. If you're prone to breakouts, make sure that any product containing dimethicone is also non-comedogenic, to avoid clogging pores, or else avoid use of the product.
For more information on controlling oily skin, follow the links on the next page.
Related HowStuffWorks Articles
- American Chemistry Council. "The Basics -- Polymer Definition and Properties." (Date accessed: December 7, 2009.)http://www.americanchemistry.com/s_plastics/doc.asp?CID=1571&DID=5971
- Cosmetic Ingredient Review. "Cosmetic ingredients found safe as used." July 18, 2009. (Date accessed: December 8, 2009.)http://www.cir-safety.org/staff_files/safeasused.pdf
- Mayo Clinic. "Acne." November 3, 2009. (Date accessed: December 4, 2009.)http://www.mayoclinic.com/health/acne/DS00169
- The Personal Care Products Council. "Glossary." (Date accessed: December 6, 2009.) http://www.cosmeticsinfo.org/glossary.php
- The Personal Care Products Council. "Talc." (Date accessed: December 7, 2009.) http://www.cosmeticsinfo.org/ingredient_details.php?ingredient_id=199
- Starch, Michael. "New Developments in Silicone Elastomers for Skin Care." 2002. (Date accessed: December 4, 2009.)http://www1.dowcorning.com/content/publishedlit/27-1060.pdf
- WebMD. "Dimethicone Top." (Date accessed: December 8, 2009.) http://www.webmd.com/drugs/drug-18321-Dimethicone+Top.aspx?drugid=18321&drugname=Dimethicone+Top