Perforations

Stamps perforated 14 were an improvement on the stamps perforated 16 as the stamps were still easy to separate but less likely to separate while the sheets were being handled.The problem was quite simply that the holes were too close together on the perf 16 sheets. Sometimes missing perforating pins caused holes to be missing from the stamps and these can also be helpful clues when plating stamps.

Interestingly, 1d reds weren't perforated by the printers (Perkins Bacon & Co) but rather by the Stamp Office of the Inland Revenue at Somerset House under the guidance of Edwin Hill, Rowland Hill's brother. The full story of the origin and development of the perforation of the line-engraved stamp is told in Stamp Perforation:The Somerset House Years by Ray Simpson and Peter Sargent and well worth a read it is too.