I am trying to add only hardcovers of books by a certain author to my wishlist.  On some of them it says "Library Binding" or "school library binding"  under book type.  What exactly is "library binding?"

It is HC but with that thin plastic film covering over it.

excellent, thank you! :)

library bindings can take many forms. do a google search for a more complete picture of library bindings.

Stephanie, it's also an ex-library book sometimes with the library envelope in the back. Also it may say "withdrawn". They're bought from Library book sales.

There is one company that puts hard back covers on paperback books. Turtleback. 

So Library binding can mean a wide range of hardcover bindings. Usually a more sturdy binding designed for sale to libraries. 

Yes, there's several bindings covered under 'library binding' all hardcover IIRC.  Widest usage is probably hardcovers with a full color cover instead of a dust-jacket...remember all those old junior readers about states and presidents?  The mylar dust jacket cover doesn't really qualify as a library 'binding' it's just common for libraries to use them on standard hardcovers with jackets.

School library binding covers a wider range.  They can be the full color hardcovers, but also frequently the Turtlebacks Emily mentioned.  Which are paperbacks (often classics) that are professionally rebound with a hardcover for durability & heavy use.

Not sure what they call that new heavy clear plastic our public library applies to paperbacks tho.