I store my collection upright on a rack because it helps keep the pigments together. I try to use my nail polishes as much as I can to prevent them from drying out fast. When a nail polish starts to thicken, I use my nail polish thinner. :) It is a life saver. It’s inexpensive and it will save your polish with just a few drops. Thanks for the question, I answered the best I could.

If anyone has additional info.. I’d like for you to share. <3