So, what is actually perforation? Perforation of a stamp is the pin holes on stamp sheets created by perforator (comb) so that the stamps could be parted into single pieces easily. If without perforation, stamp sheet has to be cut into single pieces by a pair of scissors or knife. If one pays extra attention on these pin holes (perforation), one would notice that some stamps have pin holes very close to each other and some have pin holes more distant to each other. The distance between two pin holes is said perforation size. The standard way of describing perforation size is the number of pin holes for a distance of 2 cm. If there are 12 pin holes for a distance of 2 cm, the perforation size is said P12. Of course, there is a special instrument (perforation gauge) to measure perforation size. One needs to lay the perforation gauge on a stamp, and then move the perforation gauge up or down along the stamp until the lines of the gauge overlaid the distance of pin holes perfectly. The reading of perforation size is given on the side of the gauge.
Of course, one could discover perforation varieties by overlaying two stamps of different perforation sizes. The pin holes of these stamps are just mis-aligned as shown in the figure below.
The perforation of a stamp is normally written by a formula below:
P a x b
P is the abbreviation of “Perforation”
a is the value at the top/bottom side of a stamp
b is the value at the right/left side of a stamp
If the top/bottom reading is 12 and the right/left side reading is 14, then the correct way of writing perforation size is P12x14. If both the top/bottom and right/left sides are 12, then it could be written as P12x12 or just P12. The higher the perforation value the closer the pin holes, meaning that the stamps are easier to be separated. Malaysia recent commemorative stamps normally have four perforation values – P12, P13.5 P14 and P14.5. On the other hand, the Malaysia definitive stamps (agro-based product, fruit, garden flower and bird) have perforation values P12, P13.5, P13.75, P14, P14.5 and P14.75.