The process involved coating the teeth with a solution which was prepared by dissolving iron filings in vinegar, this base solution was then mixed with vegetable tannins from sources such as gallnut powder or tea powder. Coating the teeth with this liquid helped to prevent tooth decay and enamel decay. The dye had to be applied almost daily, The contrasts of colour which are so important in aspects of what is considered beautiful in Japan are greatly relevant to this practice.
References the the practice of Ohaguru can be found in classic Japanese literature such as Genji Monogatan and Tsutsumi Chunagon Monogatari. Often when a bride-to-be of the Heian period was to enter her future husband’s family’s home for the first time, beforehand she would ceremoniously apply her first ohaguro. When a maiko, or apprentice geisha, was to graduate to the next stage of her training, she would collect the ingredients required to make her first ohaguro application from her friends and associates.
