In his book, Line Engraved Security Printing: the Methods of Perkins Bacon 1790 to 1935 Banknotes and Postage Stamps, Gary Granzow, traces the development of engraving on steel, the mechanics of design transfer, hardening, inks, perforation and plate repair during that 145-year time span. This talk will focus on a number of the discoveries described in the book and a discussion on the research that lead to several of them.