Perforation is an important feature of stamp appearance. The holes made between the stamps on the whole stamp are called holes; after tearing, the concave semicircular part on the edge of a single stamp is also called a hole, and the protruding part is called a tooth, collectively called a perforation.
The earliest stamps had no holes, so it was very inconvenient to cut one by one when they were sold. In 1848, the Irish Henry & middot; Atzel invented the punching machine. On January 28, 1854, England first invented the perforated stamp. Up to now, the stamps issued by countries around the world are basically perforated. A small number of toothless tickets are specially issued to enhance the interest of stamp collectors, such as Mei Lanfang stage art and Milu.
The perforations of stamps are for easy tearing and have no other use. However, due to the different punching methods, punching effects and hole shapes, the perforation of stamps is also varied, even for the same kind of stamp, there are differences in perforation, which has aroused widespread interest of stamp collectors.
The drilling methods include linear type, comb type and disc type. Due to the different arrangement of the toothed needles of the punching machine, the disc drilling method is mostly used at present. But the hole shape also has the circle, the dot linear, the square and so on, the common is the circle. From the drilling effect, there are smooth teeth and hairy teeth. The hairy teeth are formed because the toothed needles are not sharp and the paper scraps in the holes are not cleaned. Most of the modern stamps have smooth teeth.
Stamp collectors can identify the plate, issuing time and place of stamps by studying the perforation of stamps. For example, due to the large amount of ordinary stamps, stamps with the same pattern and face value are often printed many times. In addition to the slight differences in the patterns, there are also some differences in the perforation. Therefore, the study of stamp perforation is also a part of stamp collecting.
In addition to the different shapes of perforations, there are also differences in size and density. How to distinguish it? Usually, the number of perforations in 20 mm is called the degree (P). This method was first put forward by French scientist legra in 1866 and has been used up to now. There is a special tooth measuring ruler for measuring the perforation. The measuring method is very simple. Align the perforation of a stamp with a row of teeth to teeth and holes to holes. The number marked next to the holes in this row is the degree of perforation on this stamp.
The perforation of stamps plays a certain role in the beauty of stamps. Damage to a tooth is like losing a tooth, so pay attention to protection. When washing stamps from the envelope and inserting stamps into the stamp album, be careful not to break the tip of the teeth. To keep the integrity of the perforation of stamps is not only to make the stamps perfect, but also important for the study of stamps