There are so many great tools online that it's tempting to forget all about print materials. However, there are still many useful non-digitized resources, and younger patrons might not know how to use them!
Librarians can use websites or subject guides to lead patrons to print stuff, like:
Exhibition catalogs-- find out when and how art was shown in galleries and museums
Catalogue raisonnees--a collection of every work of art ever created by an artist
Ephemera--postcards, posters, fliers, and more
Image indexes--if you can't find something on Google images
