Remember mood rings from the ‘90s? Thermochromic (aka color-changing) polishes are the same idea for your nails. These types of polish respond to temperature changes like when you are rinsing your hands in cool water or even being outside under the warm sun. Now that hand-washing 54 times a day has become a part of all of our quarantine routines, we couldn’t think of a better way to make a mundane task a little more fun by swiping on some color-changing nail polish.
“Thermochromic nail polish takes advantage of leuco dyes, which use either temperature, UV light, or pH to change from one color state to another,” says Christy Rose, founder and product developer for KBShimmer.
“Leuco dyes are chemicals that are placed into micro-encapsulations to prevent them from reacting with other chemicals. They are colored when cooling at low temperatures and when the heat rises, they become translucent revealing any colored layer underneath,” adds Jackie Truong, co-founder of LeChat Nails. “At low temperatures, the solvent remains in a solid state, converting the system into a structure that keeps the ingredients near each other. As a result, they reflect light and create color. As the solvent warms, the structure melts off and there is no visible color exposing underlying inks.” Simply: It is magical.
Thermochromic nail polish will not give a constant rainbow-like effect, however — you will usually see it switch between two main colors (sometimes seeing a mix that is in between the two, as well). Some brands allow for tri-thermal pigments to offer a great array of transitions. “It all depends on selecting a sequence of leuco dyes that perform at different temperature ranges,” says Truong.
Below, find some of our tips on what you can expect if you are new to the thermochromic look, plus a few of our favorite options when you’re ready to try it out yourself.
- You apply them just like normal nail polish.
It might look like there is wizardry involved, but thermal nail polishes go on as easy as your normal nail polish. You can use a base coat, two or three coats of color depending on your opacity preference and a topcoat to extend the life of your polish.
- Make sure you love all of its color potentials.
For the majority of the day, your nails will be the same color based on your natural body temperature and the temperature of your environment (say, if you sit in your air-conditioned home office all day). But definitely read up on the other colors it transforms to under different conditions and see if you enjoy each one. You might love the navy shade when you first put it on, but the pink it transforms into might not complement your skin tone.
- The color you see might not be the color you get.
Unlike other regular nail polishes, the color you see in the bottle might not be the color you get once it is dried on your nails. “For thermal nail polish, the magic really is in the heat. Most of us keep our homes around 72 degrees. The thermal polish needs a slightly higher temperature, usually around 86 degrees to start changing. So, that bottle is the ‘cool’ color, and when applied on your nails, the ‘warm’ color starts to show. In addition, most thermal polishes will dry to a satin finish, so follow up with a quick-dry topcoat for that shiny, fresh from the bottle look,” says Rose.
- Try growing out your nails.
“Thermal polishes are entertaining to wear. Those with long nails will more easily experience multiple colors at once, but even short nails will see changes while holding an iced coffee, sipping a warm tea or while washing your hands,” says Rose.
- The thermal sensitivity may vary.
Some color-changing nail polish can be so sensitive to temperature changes that it could even create a cool ombré effect (the tips of your nails being a different color than the rest depending on how cold your fingers usually are). “The color transition is due to a change in the crystalline structure conformed by the combination of the chemical components and consequently, the effect of the temperature on the components determines the melting of the structure and the heat required to show a specific color,” says Truong. It just means you may need to do some trial and error to find one that works for you.
- Thermochromic nail polishes have a shorter shelf life.
“Thermal pigments are more sensitive by nature due to those microspheres. Over time, the solvents in polish can break the encapsulation, causing one state of the polish to become permanent,” says Rose. Normal nail polishes can last for two years, but the thermal polish will work for 6-12 months if you want the optimal results. Make sure you also store your nail polishes (of any kind!) in a cool, dark space to extend its life.
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