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.
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 mark
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.
CK Blue Chalk Line Refill, 100g