Always tighten the cap on your nail polish bottle tightly. [3] X Expert Source Mia RubieNail Artist Expert Interview. 23 April 2020. A loose seal can let air in or lead to messy cap threads.
If you have room in your refrigerator, this is a good place to keep your polish. Otherwise, keep it in a closed cabinet (rather than on the counter).
You can also shake the bottle gently, but shaking vigorously can create bubbles which can make the polish apply unevenly the next time you use it.
Moisten a cotton ball or Q-tip with fingernail polish remover. Try to squeeze most of the remover back into the bottle — you don’t need a soaking wet cotton ball. Gently scrub the cap threads. The dried polish should start to dissolve. If necessary, re-soak your cotton ball or switch to a new one. Finish by wiping the clean cap threads with a tissue. Try not to let nail polish remover get into the polish itself. This can affect the texture of your polish — it may even ruin the whole bottle if enough gets in.
Be sure to do this somewhere well-ventilated. The fumes from lacquer thinner can be hazardous in tight spaces. If the weather is good, go outside. Otherwise, open a door or window and turn on a fan. Lacquer thinner is available at most hardware stores for just a few dollars per can. The smallest sizes are normally about a quart, so one purchase will last you a long time. You can also use nail polish remover or acetone, but be sure to only use a few drops. Otherwise, the polish might become too watery. [7] X Expert Source Mia RubieNail Artist Expert Interview. 23 April 2020.
If your polish is still too thick, add more thinner a drop at a time and continue stirring. When your polish is the correct consistency, stop adding thinner.
Note that this can affect the color and consistency of your polish. It shouldn’t outright ruin it, however. You should still be able to use it when it’s liquid again.
