I enjoy having a set of books so everyone can look at the same artwork
without problems. Sometimes the slide projector is just inconvenient for
just one slide. This way we can look at and discuss the work quick then put
the books away.
I have a classroom set only. Sometimes when I have a sub they come in handy
also. We have some subs that don't want any kind of studio art going. The
students can take turns reading and so forth.