Glossary

Album

Specially printed sheets, bound with springs or rings. The sheets have printed illustrations or frames marking where the stamps go. Can be: complete, detailed, beginner, or thematic.

Strip

A row of several stamps joined together, not separated, in a horizontal or vertical row.

Bundle

A packet of one hundred identical postage stamps, stacked and wrapped in cellophane tape, resembling a stack of banknotes.

Charity (semi-postal) stamps

Issued for a charitable purpose. The surcharge added to the stamp's value (marked with a plus sign) usually goes to a charity fund.

Block

One or several stamps printed specially on small sheets of good-quality paper, with margins left around the stamps. Blocks may be perforated or imperforate.

Sheetlet with illustrations

A sheet of stamps that contains printed illustrations and vignettes in the margins of the sheet.

Postal souvenir sheet

One or several postage stamps, usually with different subjects, printed on a small sheet with a frame and additional text, drawings or ornaments.

Souvenir block

A block printed from the same die as the regular postal block, but without a face value, or with the face value crossed out.

Express mail

A special postal service for delivering letters faster than usual. Special stamps are issued for this purpose.

Validation of postage stamps

Means "putting into use" a postal issue.

Printing method

The accepted term for the technical method used to print stamps. There are three main types: relief (letterpress), intaglio (recess) and planographic (flat) printing. In relief printing, the raised parts of the printing plate are printed. In intaglio, the recessed and engraved elements are printed. In planographic printing, the printing surface is flat.

Vignette (label)

An additional part attached to some postage stamps, separated from them by perforation. On its own it has no franking value, while the stamp retains its value without it.

Watermark

Translucent figures, numbers or letters found in the paper on which postage stamps are printed, created during the manufacturing of the paper. They are colourless but more translucent than the rest of the paper.

Military mail

Stamps issued for franking letters for regular soldiers and mobilised citizens. No Bulgarian stamps were ever issued specifically for military mail.

Putting into circulation

The release of postage stamps of a given issue at post office counters. The act by which the validity of the stamps for postal use is recognised.

Airmail

Carriage of postal items by air, by aeroplane. Special postage stamps called "Airmail" or "Aeroplane stamps" are issued for this purpose.

Commemorative stamps

Issued specially to mark an event, historic moments and other occasions, as well as to honour the memory of distinguished people.

Design error

A factual error made when preparing the design of the postage stamp: date, image, text.

Production (process) error

A deviation from the normal appearance of postage stamps, without periodic recurrence in the printed sheet or print run, caused by a technical fault, omission or incomplete step in the production process. The most common errors are: missing perforation, missing colour, and shifted overprint.

Gum

The adhesive applied to the back of stamps so that they can be stuck to postal items. Older stamps had gum made of gum arabic and glycerine; newer ones have synthetic gum. The gum may be colourless, clear or slightly tinted.

Pair

Two stamps joined together, not separated, in a horizontal or vertical row. Pairs printed in opposite directions are called "tête-bêche".

Duplicates

Stamps that a collector owns in excess of what is needed for their collection. These are used for exchange.

Expert

A person with special training and philatelic knowledge who, through comparison and other comparative methods of examination, is able to determine whether a stamp is genuine, partly altered, or forged.

Expert mark

The mark that an expert places on the back of a stamp they have examined, certifying that the stamp is genuine.

Expertisation

Submitting a stamp or a reprint of one for examination, to determine whether the stamp is genuine or forged, as well as to assess its condition.

Postal label

An adhesive label, often designed like a stamp, indicating the type of postal item. On its own, without postage stamps of the corresponding face value, it is not valid for paying the postage fee.

Perforation gauge

A tool used to measure the perforation size of postage stamps.

Issue (emission)

The issuing of individual stamps or a whole series of stamps in a specific print run, for a specific purpose or occasion. According to their purpose, issues are divided into: definitive, special, charity, parcel post, airmail, official, postage due, and express mail issues.

Block of four

Four stamps joined together in two rows.

Booklet

Small sheets with identical or different stamps, intended for domestic or international correspondence, inserted in a hard cover.

Maximum card

A postcard with a stamp of closely matching subject affixed to the front, cancelled with a dated postmark, first-day cancellation or special postmark.

Catalogue

A specially published book containing descriptions of the various types of stamps, as well as their prices. Catalogues are divided into: specialised, general, "KINDER" (children's), and thematic.

Condition of stamps

The state in which stamps are found. First quality means preserved natural colour, intact perforation, original gum, clean back, without scratches or rubbing. Second quality - stamps with defects.

Kiloware

Cut-outs from postal envelopes, cards or various documents, together with the cancelled postage stamps affixed to them.

Classic stamps

Stamps issued by various countries up to the year 1890.

Stockbook

Cardboard sheets, bound or joined with rings or a spring, with stretched strips of transparent material, used to arrange and store stamps.

Postmark

The stamp of a post office used to cancel stamps so that they cannot be reused afterwards. It usually contains the name of the post office and the date the letter was accepted.

Die (plate)

A printing element in the printing form.

Collector

A stamp enthusiast who collects and arranges them in an order of their own choosing.

Collection

A gathering of postage stamps, arranged in an album or stockbook according to the taste and understanding of the individual collector. Collections can be: general, thematic, or specialised.

Silk thread

Some countries print their stamps on paper containing a coloured silk thread or fibre, as a means of preventing forgery.

Curiosities

A deviation from the normal appearance of a single stamp, caused by chance occurrences during the printing of individual sheets or during perforation - shifted, inverted, or double overprints.

Legend (inscription)

The text on a stamp that explains: the country of origin; the face value; the subject; the occasion; the year of issue.

Stamp hinges

A strip of small pieces of transparent paper with adhesive on one side, used to attach postage stamps to album pages.

Miniature sheet

A sheet of postage stamps that does not contain printed illustrations or vignettes in the margins of the sheet.

Want list

A list of the stamps a collector is missing. It contains only the catalogue numbers according to a specific catalogue.

Margin

The white border surrounding a stamp. A quality stamp should have equal margins on all sides, i.e. be well centred.

Postage due stamps

Issued specifically to charge for letters submitted without stamps affixed, or with stamps of insufficient value affixed.

Sheet margin inscription (millésime)

The margins bordering the sheets of postage stamps. They may be blank, or may bear printing-order data, colour proofs, additional text, drawings, ornaments, symbols, or control numbers.

Inks

An important element on which the quality of stamps depends. They must meet specific requirements depending on the type and technique of printing.

Perforation

The characteristic shape of the edges of postage stamps, resulting from their separation from perforated postal sheets or blocks. Perforation is carried out to make it easier to separate stamps from the sheet and from one another, by evenly punching holes along the dividing spaces between the stamps. By shape, the perforation may be round or diamond-shaped, giving the stamps a toothed or serrated edge. By the method of perforation, it may be line, comb, or harrow perforation. In line perforation, the horizontal and vertical spaces between the stamps are punched successively. In comb perforation, three of the spaces bordering the stamps in one row of the sheet are punched simultaneously. In harrow perforation, all the edges of the stamps on an entire printed sheet are perforated simultaneously. The perforation size (gauge) is determined by the number of teeth within a distance of 20 mm along the edges of a stamp, and can be measured with a perforation gauge or a ruler.