Things You'll Need
Nail polish remover
Thinner containing bromopropane
Whiteout, sometimes called correction fluid, covers up mistakes made on paper. There may be times when the correction fluid isn't needed for a long period of time, and during that time the solvents evaporate into the air. The whiteout becomes thick and dry. But you don't have to throw away your bottle of whiteout if this happens—there are a few tricks you can use to revive it.
Nail Polish Remover
Drip three drops of nail polish remover inside of the whiteout bottle. Use an eyedropper to do this.
Close the lid to the whiteout bottle and shake.
Repeat with two more drops if the whiteout is still not thin enough to use.
Use an eyedropper to administer three drops of a thinner containing the ingredient bromopropane to the whiteout bottle.
Replace the cap on the whiteout and shake vigorously.
Check to see if the whiteout is thin enough to use: Write a letter on a sheet of paper, then cover it up with the whiteout. If it goes on smooth and is not clumpy, it's done. If not, repeat the steps using two drops of thinner.
If you are using a different brand of correction fluid, look for a thinner made specifically for it. Office supply stores sell these thinners.
Thinner is highly flammable. Do not smoke or light a match while using it.