Crayola Sidewalk Chalk is a molded chalk made of Plaster of Paris and color pigments. Although it is designed to be used on sidewalks and driveways, the chalk contains colorants, which may stain clothing and other household surfaces. If the chalk is used on a newly poured sidewalk or driveway, there is a possibility that the open surface pores in the concrete could absorb the colors. We suggest testing the Crayola Sidewalk Chalk in an inconspicuous area and then try washing it away with water. In most cases, the chalk markings wash away with the first rainfall if it is used on a paved or poured surface that is more than two years old. Crayola offers stain removal suggestions as a service to consumers. You can find this information by going to http://www.crayola.com/canwehelp/staintips/stain.cfm
. Please bear in mind, all the stain removal suggestions we offer have been tested in our laboratory but we are unable to guarantee the results. We recommend you test our suggestion in an inconspicuous area first. If you need further assistance, please call (800) 272-9652 weekdays between 9 AM and 4 PM Eastern Time and a representative will be happy to assist you.