Printing press demonstration at Ephrata Cloister. One of the most important Colonial presses was the press of the Brotherhood, on which the Martyr's Mirror of the Mennonites, largest book published in Colonial America was printed at th e Ephrata Clositer. Printer shown operating the Cloister Press is Harry F. Stauffer, who has restored the press so that the art of printing once again flourishes in the cultural center of Pennsylvania.