Line marker (sports)

They were originally developed to mark out lawn tennis courts on grass, but later also became used in many other sports with outdoor pitches.

[2][3] As the game progressed, the ploughed lines would become indistinct from repeated foot traffic, making calls difficult and causing disputes.

[2][3] The use of whitewashed or chalked lines was developed by William Wing, a Cincinnati Red Stockings groundskeeper.

[6] Lines are marked by applying a very light or very dark material which will stand out against green turf, dirt, clay, or flooring.

[1]: 126 Proprietary marking solutions, sometimes mixed with chalk or whiting, are considered semi-permanent on turf.