A typical Journey Cloth
A Journey Cloth is a small cloth with a symbol on it, with the cloth affixed to a wall or other vertical structure. Yeesha placed the cloths in each Age that was important to her overall Journey, as a path to follow for those explorers who sought to learn from her. Each Journey Cloth bore a separate symbol, and each Age had seven cloths.
The cloths themselves were likely made by Yeesha, although given that they resemble other Bahro technology, she may have learned their creation from them.
Touching a journey cloth would create a similar cloth "bookmark" in an explorer's linking book in their Relto library. Touching the bookmark would act like touching the viewing page, except it would take an explorer to the location of the last journey cloth they'd touched instead of to the normal link-in point.
Thus, if an explorer wanted to avoid a long trek from one end of an Age to another, or if their activities would mean cutting off access to another part of the Age, they could use a bookmark to return to a specific journey cloth instead of starting over from the beginning.
In Yeesha's first journey, touching all seven cloths in an Age was the requirement for opening the Journey Door, although the requirements in each Journey varied.