Has your nail polish become thick and chunky because it has been lying
for too long? Most of the times, old Nail polishes begin to thicken
around the bottom of the bottle. To make them thin, add a few drops of
nail polish thinner or nail polish remover.
Before applying a new coat of nail polish, soak your nails in
luke warm water for 5 minutes and rub off the leftovers of the previous
nail polish gently with a finger.