This is something I hear from people from time to time: I like to take a break from nail polish so my nails can breath. Nails need to breathe, right? Well, nails don't breathe. They don't need air. They are made of hard keratin protein like your hair. The nail plate is actually dead tissue that does not breathe so it doesn't matter if nails are covered with polish. Nails are porous and they do absorb water though. The water nails absorb evaporates naturally from the nails. Nails are softer and more pliable when wet. They tend to flatten when wet and curl when dry. This constant flattening and curling can weaken the nails and cause peeling. Many people find that wearing polish lessens the amount of flattening and curling helping their nails to be stronger. There are some people can get dry and flaky nails from wearing polish. It's not because the nails need to breathe, though. It's because they have become dehydrated from the chemicals in nail polish.