Line Engraved Security Printing: the Methods of Perkins Bacon 1790 to 1935 Banknotes and Postage Stamps by Gary Granzow The first major work on engraving postage stamps since Jamex Baxter's 1939 book; Printing Postage Stamps by Line Engraving, is on the nature of the engraving and not on specific stamps. An original approach to the research and understanding of line engraving on steel and the security printing it made possible. While much of the focus is on the evolution of line engraving in the UK, the findings apply to line engraving in general. Previously students have studied thousands of stamps and dated envelopes to deduce how the stamps were made and why they appear as they do. Gary has traced the development of engraving on steel, the mechanics of design transfer, hardening, inks, perforation and plate repair from 1790 to 1935 by studying primary sources and patents. Using this approach, he has made several basic discoveries and corrected a number of erroneous conclusions in the literature. 320 pages, 180 illustrations, many in colour.