Chalk lines are necessary for laying out perfectly straight lines for nailing or laying tile as well as numerous other projects. Tajima"s Chalk-Rite 10.5 oz. snap line blue powder chalk is wind resistant, water repellent, extra strong chalk made to leave long lasting marking lines. It is fade resistant and makes a sharp and extremely bold marking line. It has been specially formulated to prevent caking and clumping and comes in a convenient, easy pour, moisture-proof bottle with a screw cap nozzle.