Usage and Grammar

Q. For the labels on a wall at an art exhibit, should it be “courtesy of the artist” or “courtesy the artist”? I am under the impression that “courtesy of” is acknowledgment as well as thanks to the second party for providing something.

A. The phrase “by courtesy of” is typically shortened to “courtesy of.” In credit lines and the like, where space tends to be limited, the phrase has often been further shortened to “courtesy.” In the context of giving credit, all three forms mean the same thing (something like “thanks to” or “kindly provided by”). Pick one and be consistent, though “courtesy of” is probably the best choice in most contexts, room permitting.