Common nail polish ingredients include film forming agents such as nitrocellulose, resins, and plasticizers, such as castor oil, and coloring agents such as soluble dye and pigments. While every manufacturer has their own unique blends, most brands use these primary ingredients. The mixture produces good coloring, full coverage, and long lasting effects.
Nitrocellulose, a mix of liquids and minuscule cotton fibers, is often the primary ingredient in nail polish. Also known as cellulose nitrate, nitrocellulose binds the other nail polish ingredients together and produces a film, which allows the nail polish to dry evenly. Used alone, nitrocellulose becomes brittle and chips easily. Manufactures often blend the ingredient with resins and plasticizers to keep the nail polish supple enough for use.
Resins and plasticizers give the nail polish a degree of flexibility. This flexibility allows the consumer to apply the nail polish with the brush without the polish drying too quickly or forming unevenly on the nail. These nail polish ingredients also help the nail polish last longer after being applied to the nail. Resins form a hard shell that is resistant to soap and water, keeping the color on the nail longer. Manufactures use a mix of amyl and butyl stearate, castor oil, acids, and glycerol as resins and plasticizers.
Early nail polish ingredients included soluble dyes to give the polish color. Modern nail polishes, however, contain pigments, which produce a deeper and more even color. The pigments are ground by a machine and introduced into the other nail polish ingredients slowly to ensure even distribution.
Pigments will not bind to the other nail polish ingredients on their own. Manufacturers use solvents to help bind the pigments together, and to allow the pigments to blend with the other ingredients. These solvents help keep all of the ingredients blended and uniform, giving the nail polish a smooth appearance when applied to the nail.
As the science behind nail polish ingredients develops, better ingredients will continue to replace older ones. For example, manufacturers used formaldehyde as a binding agent in older versions of nail polish. As more sophisticated materials became available, the manufacturers of some brands began to discontinue the use of this potentially harmful ingredient.
Nail polish ingredients tend to separate inside the bottle. Particles from the ingredients will settle at the bottom of the bottle. Consumers can extend the life of the nail polish by storing the polish in the refrigerator or shaking the bottle before each use.