The advent of printing with movable type is properly regarded as the most important technological event in modern cultural history, yet its earliest history is shrouded in mystery. The Davis proton milliprobe has enabled scientists and humanist scholars to collaborate in unlocking the secrets of earliest print, focusing on the contribution of Johannes Gutenberg. The 42-line Gutenberg Bible is not only the first book printed by movable type, it is considered by many to be the finest book every printed. Unfortunately very little is known about the materials and techniques used in this first large scale printing operation. In October 1982 we had the unprecedented opportunity to examine page-by-page the inks, papers, illuminations and binding of volume I of the Doheny Gutenberg Bible. A similar study of the Lilly New Testament (most of volume II) was undertaken in March 1983. The results, some wholly unexpected and very exciting, add a large new body of information about this great work, and give us new enlightenment on the day-to-day production of this first and most important printed book. Moreover, the discovery of the uniqueness of the ink in Gutenberg's Bible, combined with our ability to taken minutely detailed and non-destructive elemental "fingerprints" with the milliprobe beam of all man-made papers and inks, gives us a weapon that has never been available before to investigate some of the controversial basic questions in the history of the origins of printing technology.