Another thing we can glean from these records is how expensive/labor-intensive it was to produce them. If we find that in a certain time period, people were onl

Another thing we can glean from these records is how expensive/labor-intensive it was to produce them. If we find that in a certain time period, people were only writing about business and government as opposed to personal correspondence or frivolous things, then we can assume that the medium might have been costly at the time, and/or that people did less-official communication through media that were less durable, like paper or the brain of a messenger.