Years ago I taught an evening class in philately at Temple University. The class was made up mainly of well educated people who were either getting back into collecting or who were, never having been stamp collectors, thinking of trying our hobby on for size. At one point after a few weeks the topic of plating was introduced. Most engraved Nineteenth Century stamps were engraved from a single die that was entered into a large plate usually 100 times to make plates of 100. In the earliest period of stamp issuing, such entering of the die to the plate was done by hand, rocking the hardened steel die into the softer unhardened steel or copper plates. The steel of the plate was still pretty hard and considerable effort and rocking back and forth was necessary to make the die impression in the plate. Different entries show different degrees of design strengthening at different places as they were rocked in inconsistently and it is from such tiny differences that philatelists have been able to plate early stamps-that is tell from which position from the sheet a single stamp has been printed. Early platers used jig saw puzzle like skills using sheet margin singles and multiples to ascertain plating information and proof. By about 1860, production of postage stamp plates became more machine driven so that differences between entries of the die all but disappeared. Thus plating can usually only be done on the earliest stamp issues. So I was showing my Temple class how plating was done and we were looking at design differences magnified twenty or thirty times when one woman exclaimed "Such minutia-this is a hobby of millimeters". I had to agree and I thought we had lost her. But no, she loved the precision. She was an educator and her world was one of relative evaluations and a hobby where something was one thing or another with no ambiguity was very appealing to her. She came back to every class after that and now has one of the better plating collections of US 1851's around.