《太平广记·卷四百八十·蛮夷一》
在汉朝时候，上将出征，以及出使极远的国家，多用兰金泥作官印的封泥。
当汉世，上将出征，及使绝国，多以泥为印封。
During the Han Dynasty, when a general went on an expedition or an envoy was sent to a faraway country, Langing mud was often used as sealing mud for official seals.