The mention of writing materials, in the thread on beech/book, reminded me of an interesting word in common use, which has an uncommon and little-known etymology: DIPLOMA.
Diploma meant originally (more or less) “a document folded into two”. The earliest diplomas were certificates of Roman citizenship, issued by the Emperor to non-Roman citizens who had completed 25 (or 26 in some units) years’ service in the Roman army. They consisted of two sheets of copper alloy, engraved with a certified copy of the Imperial decree of conferral of citizenship, and with particulars of the bearer and his service. The two sheets were bound together and sealed. Ex-soldiers armed with such a diploma could present it to the local governor of the province where they settled, get themselves inscribed in the local register of Roman citizens, and usually receive a grant of land. The diploma was, in effect, an official letter of introduction: hence, in later cultures, a “diplomat” came to be a person armed with official credentials from one government to another.
a number of military diplomas have survived (a few, almost intact) and are highly prized by archaeologists. Google has some pictures of them.