Perforations

Perforation Guide

Perforations are holes punched through paper to guide the tearing of the paper. The holes are made using a row of hollow needles. Perforations are measured using the number of pins per two centimetres.

The first Discworld stamps to be issued, the Ankh-Morpork definitives, were perforated at the Bath Postal Museum using the rare Victorian stamp perforating machine. The machine had not been used for years and it took trial and error to get acceptable perforations. The initial attempt caused the sheets to rip. These became to be known as rat-nibbled.

It was later that it was discovered that beeswax rubbed onto the needles would improve the perforations. Unfortunately, the Museum closed in September 2023.

There are other sets of perforation used on the Discworld stamps. Machine, Wincanton and Rat Clawed perforation plus the Wrinkly and Straight Cut or Unperforated.

After careful calculation the sheet looses about 3.67% of its weight after being perforated which for an A4 sheet is about 0.18 grams.

You can read about perforations here on Wikipedia and here on the Stamp Bear sites

And an excellent site on Perforating machines.

Bath Perforation

The perforations are 12 holes per 2cm.

The perforations were done by hand by Terry and Bernard in single rows first in one orientation then in the other. This caused inconsistencies in line up and stamp borders.

The three separated edges show the ragged pre-beeswax result whilst the righthand edge shows a more regular result after the beeswax. As ca be seen on the righthand side there is a blind, missing, perforation usually indicating there is a missing pin.

Some of the early blue triangles were only part perforated on the Bath machine and completed with the Wincanton perforator.

Machine Perforation

The perforations are 13 holes per 2cm although the early Penny Patricians were 13½ holes per 2cm.

The perforation are made in one pressing which ensures a consistant and regular border to the stamp with aligned holes. Some runs were from Enschede in Holland using a comb perforator.

Perforation examples:

SHS-AM0003-Am - Ankh-Morpork 1p: 12/2cm

SHS-AM0004-Ap - Ankh-Morpork 2p: 13.5/2cm

SHS-AM0072-Ae - Unseen University 1p: 14/2cm

SHS-AM0073-Ae - Unseen University 1¼p: 14.5/2cm

Wincanton Perforation

The perforations are 10 holes per 2cm.

The perforations are made by hand one row at a time in each orientation. Like the Bath perforations the perforations are inconsistent and at slight angles to the horizontal and vertical. The stamps will have irregular borders and the junction between the horizontal and vertical rows result in mismatched holes (see bottom right hand corner in illustration.)

These are the most common of all the perforation mainly it is cheap. Bernard has a poor chap chained in the workroom who has to punch out 10,000 perforations a day before he is allowed food and drink.

If he fails to achieve the quota or perforates across the stamps he is beaten and goes to bed with out the dumpling supper. Ian still prefers this life to his collage days when he cried himself to sleep so he would have something to drink in the morning.

Rat Perforation

The more usual term of rat nibbled is a misnomer as no self respecting would use their teeth on gummed paper. It leave a very nasty taste after the first 50 sheets.

The perforations are difficult to estimate as each rat has a different claw spacing.

Truthfully, Bernard devised a device made up with pins, rubber bands and wood to make the perforations. The device was erratic causing the random holes and tears.

The perforations are made one strip at a time in each orientation. Like the Bath perforations the holes are inconsistent and at slight angles to the horizontal and verticle and have irregular borders.

Wrinkly

The Wrinkly, or wavy cut, has not appeared often. Its first appearance was with the Blue Bernard. The only other stamps to appear with the three green rat stamps.

The waves are irregular and it appears the are created by repeat cuts.

The edges being cut and not perforated means there can never be a sheet, only individual stamps.

Edwardian Perforator

The perforations are 11 holes per 2cm.

These stamps were not perforatored by the machine owned by the Cunning Artificer. The Edwardian machine was restored by a local printer and a few sheets were perforated as a test.