Nail polish is a popular fashion accessory that has been used by women for hundreds -- if not thousands -- of years. The Tour Egypt website explains that ancient Egyptian mummies show traces of henna on their nails, dying them red with the henna and using other natural products to enhance beauty. In the 21st century, most nail polish is found not in nature, but in small bottles at pharmacies and beauty supply stores. Occasionally, these polishes are a bit on the thin side, resulting in streaks and a watery appearance when applied to nails. Thicken these polishes at home to ensure an even, streak-free manicure that will last longer and will be less likely to develop chips or cracks.
Purchase the thickening agent. While there are a variety of different types of thickening agents currently on the market, xanthan gum powder is the one most commonly used in food and beauty products. In most cases, it can be found at health food or beauty supply stores. Individuals who do not have access to these facilities may be able to obtain it through online retailers.
Create a work space. Removing nail polish from a wood, marble or fabric work surface can be a very difficult process. To avoid possible spills, thicken your watery nail polish in an area that is free from clutter, debris or dirt. The ideal workspace should be relatively sturdy, and should be covered with a newspaper or paper towels. Individuals who develop headaches or nausea when working with nail polish may want to choose an area that has easy access to ventilation through a window, door, vent or fan.
Add the xanthan gum powder to the nail polish. To avoid the accidental addition of excessive amounts of the product, use a teaspoon to scoop out a small amount of the powder. Pour it directly into a nail polish bottle that has been opened. Place the cap back on the opened bottle of nail polish, and roll the bottle between your hands until the xanthan gum powder has been equally distributed.
Evaluate the nail polish. Apply a small amount of the product to a finger or toenail. If the polish is still too thin, add a bit more thickening agent. Test the polish after each addition of xanthan gum powder to avoid making it excessively thick.
Xanthan gum powder is sometimes made from corn, wheat, soy, or other products that are known allergens. Individuals who have severe food allergies should research the products they are considering carefully before adding them to their cosmetics.