A Chalk line or also known as a Chalk box is a simple hand tool that consists of a box filled with chalk powder with a reel of string inside it. The chalk lines are a tool for marking long, straight lines over distances onto the surface of an object to provide accurate guides where using a ruler or straight edge tool would be impractical. On the end of the chalk powdered string is a metal hook which can be attached to an object at one end and then reeled out across the surface and pulled tautly. Once the chalk string line is in the correct position it can be plucked at its centre and the tension in the string will make it snap back down and create a chalk line on the surface of your object. Chalk lines are typically used to mark lines on relatively flat surfaces. This chalk line tool provides accurate guides prior to cutting, laying tiles, levelling posts, handing wallpaper and many other tasks and is mostly used in carpentry.Chalk line refills are dry, powdered chalk in various colours used to replenish the dye in a chalk line. Chalk lines are simple tools used for marking long, straight lines on flat horizontal or vertical surfaces.What are chalk lines used for?Chalk lines are commonly used to mark out lines between two points and are used when the straight line required is longer than can be practically marked by hand using a straight edge. They’re taut strings coated with loose, coloured chalk. The string is drawn across a flat surface between two points and tightened. When the string is plucked it sharply rebounds against the surface and its powdery chalk coating is transferred onto the surface along the line where it struck. Chalk lines are commonly used in construction and carpentry to quickly and efficiently markHow do chalk line refills work?The powdered chalk in chalk line refills is poured into the chalk line’s reservoir. When the line is drawn out through the reservoir the coloured chalk coats the string.