This paper describes some aspects of the Wentzel collection at the George Eastman House, and points out some of its value as a research resource. Wentzel worked for several European photographic manufacturers during the period 1900-1920, and later emigrated to the United States. The collection consists of numerous manufacturers' instructions for the various photographic papers and processes; a number of examples of prints on some of the papers; and other miscellaneous items relating to early 20th century photography.