Special formulation thoroughly removes all chalk particles and residue, smudges and fingerprints from the surface, leaving boards clean and bright. Improves contrast which makes reading and writing clearer, easier on children's or adult's eyes. Fast clean-up saves labor and prevents dusting. To clean, simply spray a SMALL quantity on the board from a distance of 10 inches and rub lightly with a clean, dry cloth. Best results are obtained by using a small amount of spray.