The Pitts Theology Library at Emory University has a free Digital Image Archive online. “The Digital Image Archive (DIA) presents more than 60,000 images of biblical illustrations, portraits of religious leaders, printers’ devices, engravings of church buildings, and other theological topics. They are available for teaching, research, and other non-commercial purposes. For a modest fee, the library will grant permission for use in commercial publications and will supply the publisher with high resolution .tif files for download. You can find details about requesting permission on the Permission for Use page.”

“Many of the images in the archive are taken from the Kessler Reformation Collection, one of the library’s premiere collections. The Kessler Collection consists in titles that relate to the Protestant Reformation in Germany down to 1570.  Although its focus is on Lutheran materials, it also includes works by other Protestants and by Catholics, as they entered into conversation with Luther and his followers.”