Today, most piano keys are made of plastic that resembles the bright white ivory. Keeping the keys clean is important to ensuring that they move and work properly. Keep an eye on children when they are using the piano to ensure that they don't use a marker to draw over the keys. If they do, clean the stain as soon as possible. The faster you get to the stain, the easier it will be to remove.
Things You'll Need
Soak a cloth and wring it out so that it is slightly damp but not dripping.
Squeeze toothpaste into a clean cloth.
Rub the cloth over the marker stain in a circular motion until it is gone. Use as much toothpaste as needed but don't get the toothpaste or water in between the keys as this could cause damage.
Rinse the cloth in clear water and wring it out.
Wipe the keys with the cloth to remove the toothpaste residue.
Blot rubbing alcohol directly onto the stain if it is still visible. Rubbing alcohol will remove ink stains without damaging the plastic keys.
Rinse the keys with the damp cloth.
Dry the keys with another cloth.