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Comb perforators perforate three sides of a stamp at once for an entire column or row. The process is automated and once one row or column is perforated, the perforation sheet is advanced to the next row or column. This process produces equal and regular corner perforations. This is the most common type of perforation method used for modern stamps with water activated gum.

Die cut means a metal die has been used to cut out the stamps. The is the normal means of separation for self-adhesive stamps. A stamp that is die cut with straight edges on all 4 sides is to be listed as a “die cut” stamp in colnect and not as an “imperforate” stamp.

All sides of the stamp are perforated at the same time and the corner perforations are therefore regular.

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Hyphen-hole

A stamp with no precut means of separation is known as imperforate. Imperforate stamps need to be cut out with a scissors or knife. The straight edges of perforated stamps are also referred to as imperforate edges. However, a die cut stamps that has straight edges on all 4 sides is a “die cut” stamp and it is not an “imperforate” stamp.

Line perforators consist of a single row of perforation pins that are arranged in a straight line. A sheet of stamps is perforated horizontally one row at a time and then turned 90 degress and perforated vertically one row at a time. This process produces haphazard corner perforations and can sometimes lead to stamps of different sizes. Line perfs are rarely used in modern times.

Microperforated

Pin perfs are stamps perforated with very small holes (as if by a sewing machine). The existence of pin perfs cannot be entered in the “Perforation” field in colnect and it has to be noted in the “Description” field.

Stamps that are “perforated” with horizontal and vertical cuts rather than holes.

RoulettedImperforate

Roulettedline

Serpentine means in a snake like shape (like the letter “S”). “Serpentine die cut” is quite common and differs from “die cut” by the shape of the simulated perforations. “Serpentine rouletted” also exists (such as with the early stamps of Finland) but on Colnect it cannot be listed differently from ordinary “rouletted”.

Serpentine Roulette

Serrated Roulette