Slovak, Czech and Czechoslovak stamp:
Slovak self-adhesive postage stamps separated by cutting
Overview of Slovak self-adhesive postage stamps separated by cutting and types of cutting.
Classical separation of postage stamps
Non-serrated (non-perforated) postage stamps are separated from their counter sheets, printing sheets or sheetlets by cutting or trimming.
Serrated (perforated) postage stamps are separated from their counter sheets, printing sheets or sheetlets by breaking the narrow bridges around the perforation holes to form serrations around the whole or part of the postage stamp. The perforation tool is most often a circular hollow perforation needle, but may also have a different shape e.g. oval, star-shaped or cross-shaped.
Other perforations of Slovak postage stamps
Self-adhesive postage stamps
The self-adhesive postage stamps are made on special paper and are separated from the substrate by cutting so that only the top paper with the printed postage stamp is cut.
Manufacturing errors of self-adhesive postage stamp cuttings
There may occur several cutting manufacturing errors (oblique, shifted, double) or even stamp booklet without cutting is known on Slovak self-adhesive postage stamps.
Summary:
Contact the author of the article: Rudolf Sulej