Pour the water into a small bowl and stir in 1 tablespoon of salt. Stirring, slowly add ½ to 1 additional tablespoon, stopping when the water is fully saturated and the salt stops dissolving.
Dip your paintbrush in the salt solution and paint the outline of two eyes and a mouth for your ghost, making sure not to fill in the circles with paint.
Paint a body for your ghost and fill in the shape with salt paint, leaving the inside of the eyes and mouth untouched.
Holding down the paper with your hand, use a hair dryer to help the paint dry. As it dries, the ghost you painted will magically turn white, and you'll be able to see it! (You can also allow the paint to dry on its own, but this can take up to 24 hours, so using a hair dryer will make things more interesting for your kids.)
Video
Notes
Experimenting with salt: Lean into the scientific component of this experiment by testing different quantities and types of salt to see what works best.