Most collectors feel that specializing in a single country qualifies them to state that they are a “specialist” when it comes to their philately. But many collectors go even further than just one country and collect a single issue such as the Washington Franklin issue of the United States. Some go even further than that and collect the plate numbers and plate number blocks and some go even further than that and collect initials that are found in the side corner margins of Washington Franklins. These initials are a form of accountability markings to let people know after a stamp was printed who was responsible for handling the plate. There are three types of initials found on these stamps (in case you were wondering whether these issues could be specialized even further). There are Printers Initials that are found in side margins and are the initials of the printer who last printed from that sheet. There are siderographer initials which are usually found in the lower left corner margin of a pane of 400 (the siderographer was the person who created the plate from the die. This was a difficult and time consuming process that entailed rocking the original die into the soft metal of the plate. The siderographer knew where to rock in the impressions because the plate was set up with lines to tell him where to impress the stamps relative to one another). And finally, there were the Plate Finishers, whose job was to eliminate these guide lines and dots from the finished plate so that they would not print on the sheet. The stamp above has the Plate Finishers initials, which are placed at the bottom right on every corner margin per 400 printed stamps. The stamp sheet for this #523 had two plate finishers as it was printed from two plates in two passes through the press (W.E.S is for Warren E Spring and A.L.C. is for Adam L Chapman). When you consider that siderographer and plate finisher initials can exist on only one stamp in four hundred and then only if an early collector thought to save them you can imagine how rare they are. And yet, though rare and sought out, they really command a startling small premium.