Gambier or gambir is an extract derived from the leaves of Uncaria gambir, a climbing shrub native to tropical Southeast Asia. Gambier is produced in Indonesia and Malaysia where it was an important trade item into the late nineteenth century. It can be used as a tanning agent, a brown dye, a food additive and as herbal medicine. The leaves of Uncaria gambir are first boiled in water. They absorb it and turn brownish in color. The leaves are then pressed mechanically to squeeze and extract liquid. This liquid is then dried into a semi-solid paste and molded into cubes, which are dried in the sun.
Gambier has been used as a form of catechu for chewing with areca nut. Particularly in the nineteenth century, it was economically important as a brown dye and tanning agent. It is still used as herbal medicine, and occasionally as a food additive.