The perforations
After 15 months of argument, the Treasury agreed a price for Archer’s patents and commissioned five perforating machines from David Napier and Sons. These steam-driven perforators were installed at Somerset House. They perforated five sheets at a time, and each one could produce up to 3,000 sheets per day. They were comb perforators, which perforated the top and both sides of a stamp simultaneously, and each sheet made 21 strokes in 21 positions as the sheets moved though the machine. Initial trials were successful and British stamps were officially perforated from 28 January 1854.
The initial gauge of 16 was, however, too fine for daily use and the sheets came apart while being handled. This was solved by coarsening the gauge slightly
