Chuan is a widely-used travel pass in all states during the Spring and Autumn and the Warring States Period. Most such passes were made of wood, with some made of silk. A typical wooden chuan was five inches long, painted with official signs and sealed with a board. The sealing marks were mostly provincial censors' seals as trusted identity documentation. A silk chuan was basically in duplicate, with each copy held by the bearer and the officer at the check point. If the two copies were the same, the bearer would be let pass. A chuan was a complement to a jie, which served as a major pass.

Jie is another tool for identity verification held by ancient envoys on their missions abroad. The name "jie", meaning "national integrity" in Chinese, was a constant reminder to the bearer of national integrity and prestige in other countries. The jie materials varied according to the bearer's position, just as the remarks go: "jade jies are used by ambassadors to other countries and horn ones are used by officials in remote cities. Jies used by ambassadors are all made of gold. Jies with a tiger mark are used in mountainous countries, those with a figure mark are used in earth countries and those with a dragon mark are used in watery countries." Here, "gold" refers to "bronze". Only a handful of jies were made of jade and bronze, most were bamboo ones.