It is confusing for the public to understand the differences between Bookbinder, Book Restorer and Book Conservator. Book Conservationist is never used, except by the uninitiated. Below are how some of these terms are commonly used — more precisely, how I wish the terms were commonly used — in the United States.
Bookbinder: Someone who makes books consisting of partially prepared materials from other crafts, rebinds and sometimes repairs older books.
Book Restorer: Someone who makes old books look an imagined “new”.
Book Conservator: Someone who preserves the historic, intrinsic, artistic and artifactual value of books through preventive measures and physical intervention.
The New York Public Library has muddied the waters even further, with a program called New York Public Library Conservators. In this case, the term “Conservator” means someone who supports or maintains NYPL financially. This adds confusion, and creates the need for more explanation. But if you have an extra $15,000.00 – $24,999.00, you can call yourself a New York Public Library Carnegie Conservator, which sounds like an endowed professional position.
Further resources if you want to read more of my rants discussing these terms:
https://jeffpeachey.com/2010/03/30/outside-of-the-text-my-work-in-book-conservation/
https://jeffpeachey.com/2010/03/11/a-future-for-book-conservation-at-the-end-of-the-mechanical-age/
http://www.bookbindersmuseum.org/the-future-of-book-restoration/ The second comment.
https://jeffpeachey.com/2013/05/07/book-conservation-and-book-restoration-and-ngrams/
https://jeffpeachey.com/2008/11/11/comments-on-clarkson-conservation-and-craft/
Peachey Conservation 