There are three types of Keson powdered chalk: 1) UltraFine: 4 to 5 usable lines struck from each chalking of the line. 2) PermaMark: 8 to 10 usable lines. 3) SiteLine: 12 to 15 usable lines. WARNING: PermaMark and SiteLine are PERMANENT, and will be visible for a year or longer no matter how you try to get them off. They will even show through light-colored paint! Hard, shaped chalk is available in half moon and railroad chalk. |