L.S. Starrett Chalk & Lines
Chalk lines are used to mark a straight line between two points that are too far apart to use a straight edge. Simply hook one end at the starting point and take the other end to where you want the line to end. Once you have the points selected, pull the line tight and lift from the surface and let it snap back into place. This will leave a line of visible chalk for you to follow when laying tile, framing walls or cutting long lengths of material.