Thanakha is a paste made by rubbing the bark of the Thanakha tree onto a grindstone with water, and then smearing it on your face. It is used as sun block, moisterizer and perfume. It is worn by all Burmese and is very common, sometimes artfully shaped like a leaf on young, fashion conscious girls.
Note that the woman above has her mouth full. She is chewing betel nut which produces a mild stimulant, red teeth and spit.The betel nut is combined with leaves and a paste and can be bought at any of the markets.
