Not intended for use on school chalkboards</br>White Chalk Sticks are made to be used on children's chalkboards.</br>This Set Includes 2 x Crayola White Chalk 12 Pack 2 x Crayola Color Chalk 12 Pack</br></br>Product Description</br></br>Quality chalk writes smoothly on most chalkboards. Makes clear?? smooth lines and erases easily. Nontoxic.</br><br/>http://www.amazon.com/gp/product/B011SNV9RA