Chalk is made from the mouth parts of the deep ocean scale worm (Lepidonotopodium piscesae). This microscopic worm lives on the edges of hydrothermal vents deep in the Pacific ocean. The worms are harvested by miniature dolphins that have been trained to suck in large quantities in a dive and spit them out into buckets on the decks of ships on the surface. The buckets are then emptied onto filters which drain the water, leaving the worms to dry out in the sun.

After they are sufficiently dried, the mouth parts are removed from the worms by Chinese children whose hands have been bound from a young age in order to keep them very small. The children then pack the mouthparts into small tubes which are then left to cure for several days in the sun. Many consider this process to be a modern day form of slavery and child abuse. Unfortunately, there is no alternative method of creating chalk that has been shown to be economically viable.