The Bureau of Engraving and Printing issued the first government-made U.S. coil stamps in 1908, but it kept refining the process for years. Bureau coils could be vertical or horizontal, with or without perforations. The Bureau also tried different perforations. In 1914, it began printing stamps on a rotary press. This made it possible to print coils on continuous paper rolls, instead of creating them from strips that were pasted together.
Unlike many coil collectors of his time, Miller appreciated the paper leader attached to the first stamp on a coil. Today, leaders are highly prized, especially when they are still connected to the stamps.