The Cresset Library is a series published by Cresset press; it has had at least three distinct lives. Before World War II a few volumes of story collections were published in the series. After the war it was reborn as a very good series of historical reprints, usually of somewhat neglected books. The books are neatly produced, with good paper (particularly for late forties where some British publishers appear to have had difficulties obtaining decent paper), and with jackets of varied colors but similar designs.
Later, the series name was used occasionally for other kinds of books. This checklist is concerned only with the reprint series.
There is a very good discussion of the series on the Series of Series website, and Wikipedia has an article on the Cresset Press.