This museum seemed to be free: just walk in! It's 4 floors on the history of paper making, writing, printing, and book-making. On the main floor there's a working mill staffed by a few people who will hands-on show you how to and help you make a piece of paper. The hours are limited, but the shop hours are less limited, and they sell all sorts of neat hand-made paper products and writing implements. Very cool. Highly recommended.
This plus the Tinguely Museum would be a great day for a kid (or the kid in you). I loved it!