The Washington Post had a recent article about librarians and rare-book people working together in a summer seminar at the University of Virginia to understand books as artifacts. There was a photo of a couple of them looking at a page of a book with light under the page so they could see watermarks.
I took out a couple of eighteenth-century books (part of that collection salvaged at library sales—Princeton and Vanderbilt primarily) and took a look at the paper. Here's what I saw:
A Summary of a History of the Rise and Development of Religious Ideas. Jena (the university town in the same principality as Weimar)
The Life, Fate, and Persecutions of the Prior Hartungus
Secret Philosophy and Character of Monks and Their Institution