Colour Varieties and Ink Errors
The colour and quality of the ink are fundamental to a stamp's appearance. Variations in ink composition, mixing, application or printing conditions can produce a wide r…
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Double Print and Pseudo-Double Print
A double print and a pseudo-double print may look similar, but they are produced in different ways. A double print results from printing the stamp design twice on the sa…
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Foreign-Body Printing Flaw
In Hungarian printing jargon, the term poloska refers to a random printing flaw caused by a small foreign particle between the printing surface and the paper. It usually…
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Ink Show-Through
Ink show-through occurs when the printing ink gradually penetrates the paper and becomes visible on the reverse of the stamp.
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Inverted Print
An inverted print is a rare and striking error in multistage printing. It occurs when the sheet is inserted into the press upside down during one printing phase, causing…
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Missing Colour or Printing Phase
In multistage or multicolour printing, one of the printing phases may occasionally be omitted, causing one or more colours to be missing from the stamp.
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Offset Impressions
An offset impression is a mirror-image ink transfer appearing on the reverse of a stamp. Depending on how it is produced, several forms can be distinguished, including m…
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Paper Fold
A paper fold is a printing error caused by creasing of the paper. When the sheet is later flattened, the affected area may appear as a characteristic unprinted white str…
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Partial Missing Print
A partial missing print occurs when ink cannot reach part of the printing surface because of an obstruction or a defect in the paper, such as a folded sheet, paper creas…
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Perforation Varieties
Stamp perforations are intended to place the printed design neatly and centrally within the perforation lines. Incorrect machine settings, misfed paper, creasing or fold…
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Plate Flaw
A plate flaw is one of the most common printing varieties. It is a recurring feature caused by a defect, damage or wear in the printing plate and appears consistently on…
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Printing on Both Sides
Printing on both sides occurs when an already printed sheet is accidentally, or more rarely deliberately, fed through the press again and the stamp design is printed on …
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