"By the late 1920s the volume of commercial mail had increased dramatically and businesses were seeking more efficient ways for processing mailings. This demand led to the development of affixing and perforating devices of ‘rolled’ (coil) stamps. Before 1914, coil stamps were flat plate printed, cut into strips, and manually pasted together to form rolls of 500 or 1000 stamps. But with the advent of the Stickney rotary press, stamps could be printed on “endless rolls” with a significant reduction in printing costs. Printing on the Stickney rotary press required two curved printing plates wrapped around a cylindrical bed called the plate cylinder. As the two plates rotated, they printed on a continuous roll of paper referred to as the web. After the printed roll was perforated and rewound, stamps were counted to their appropriate roll size and separated from the main roll and prepared paper was glued to the severed ends. The left side of the paper would become the core of the coil (trailer strip) to facilitate rolling. The right side was printed describing roll size, format of the stamp (sidewise or endwise) and the denomination. This would serve as the leader strip and become the wrapping for the roll.1" This exhibit illustrates some of these ‘leaders and trailers’.
1 From Production Characteristics of the Prexie Coils by Bill DiPaolo