Bath Perforations
The very first stamps were taken as sheets to the Bath Postal Museum for perforating, in front of the media of course; all good publicity for Going Postal. The perforating machine had good old imperial perforating pins that were spaced at 12 per 2 cm. Operating an antique perforating machine is a skill. On that first day not everything went to plan and those involved had a good laugh. Apparently many perforated sheets were unsuitable for use, and it is doubtful any stamps perforated on the Press Day ended up with collectors. Even on those deemed adequate the perforating was very rough, but would have been kept by those involved. Return visits to the museum provided the stamps for the earliest LBEs, and the roughness of the perforations could be explained by pointing out the technology level that Ankh-Morpork exhibited in the novels. It was during one such visit that one of the museum staff whispered in Bernard’s ear that a much cleaner job of perforating could be achieved by the application of a bit of beeswax to the perforating pins. So from a collecting point of view there will be stamps with the original rough, ‘rat-nibbled’ perforations and those with the neater standard beeswax perforations. Both the sports are known to exist with Bath perforations, but so far I have not seen any of the rat-nibbled sports. Do they exist?
a rough perforated
rat-nibbled stamp

Wincanton Perforations
Soon the stamps were becoming popular and more designs were being considered. It became apparent that constant trips to Bath would be impractical, so a machine for in-house perforating was purchased. This perforator produced much cleaner perforations (or was it that they had acquired the knack by then?), and these were 10 per 2 cm. This has subsequently become Discworld stamps standard (with a few notable exceptions) and is termed Wincanton perforating. Most TOA stamps issued will be Wincanton perforated.
It is worth pointing out here that the majority of the Halfpenny to the 50p Cabbage Fields stamps from the first stamp issues were printed and perforated by Enschede, the Dutch security printing firm. Those stamps were sized to fit available template sizes offered by Enschede. These are easily recognizable by the much higher quality printing and by having 13.5 perforations per 2 cm. Neither the $1 TOA nor the $5 Blue Triangle could be accommodated by that company, so once the Bath perforator was abandoned all stamps of these two values had Wincanton perforations.

The Sheets
The original sheets were printed without any marginal logos or text; just guide marks for the perforating. There were 16 stamps in two rows with the two sports occupying the two positions at the top right. No complete sheets of the green $1 stamps were sold. Individual stamps could be purchased, but the sports could only be found in the Little Brown Envelopes.
Illustrated is an un-perforated sheet showing the layout. As sheets from later printings had some marginal decoration, collectors can identify stamps from these early first print runs only if their stamp has a left or right margin which is free from any text - see pages on later print runs for details.
It may be that the first and second print runs were done by different printing firms and that this may have resulted in subtle differences in print quality or appearance under magnification, or even subtle shade differences. This is a future area for investigation.

Numbers
This is where things get fuzzy. There were three print runs of this stamp and in total 11700 of the stamps produced. There were 650 sheets with 10400 commons, and 650 each of the Falling Man sport and the Splash sport. But no-one knows how many of the first and second print runs were produced, nor how many of the first run were Bath perforated. If one judges numbers by frequency of appearance on sales on eBay then the ratio of Wincanton to Bath perforated will be greater than 20:1. However would this be influenced but retention of Bath perforated stamps (by over-sentimental; collectors) or are Bath perforated over-represented because they will generate more cash for sellers?

The Sports
As I have already said there were two original sports showing a Falling Man (replacing the lower right bird) and a Splash (with the bird returned).

The Common     The Falling Man     The Splash