U.S. Scott 542 was the first U.S. Stickney rotary press web-fed wet printed sheet stamp which was issued on May 26, 1920 and was perforated 10 x 11 by a Stickney bar and wheel perforator.
There are two interesting features that can be seen on the block below.
There are horizontal lines in the margin for aligning the perforating bars for making horizontal perforations and for the center sight gauge for aligning the perforating wheels for making vertical perforations. These lines are precursors of the future electric eye markings.
There are horizontal lines running across the back gum which are gum breaker lines that were added by the bar and wheel perforator in order to prevent the stamps from curling up. These appear to be the earliest gum breakers since they are on these first sheet stamps.
Posted 04/29/2019 08:32 am
