Tannin had a prominent role also during the two world wars, since various  leather articles and leather soles were present in the equipment of all the armies.

The boots of the soldiers were made of leather, the leather soles; leather harness were used for the transport and custody of firearms and even as components of war machinery: the transmission belts of the tanks were made in leather.

This implied the need to always have spare parts available, which made the tannin indispensable for war industry.

To ensure tannin’s supply during  World War II, the U.S. Army bought huge amounts of tannin that kept stockpiled in some secret French location.