Overview
In philately, a postage stamp block is a group of two or more adjacent postage stamps kept attached as a single unit. Collectors prize blocks for the extra information they can show compared with singles: margins, plate numbers, sheet inscriptions, and the relationship between adjoining designs.
Common types
Collectors and dealers use several standard terms for blocks depending on position and markings:
- Block of four: Four stamps in a square, often the most common collectible block.
- Corner block: Includes the sheet margin and usually shows plate or margin inscriptions.
- Plate block: A block that includes a printed plate number from the sheet margin.
- Gutter block: Separated by the sheet gutter; useful for showing printing alignment.
- Se-tenant and tête-bêche: Mixed or inverted adjoining designs that are collected as blocks for their visual interest or printing oddities.
Why blocks matter
Blocks preserve contextual features lost when stamps are separated: marginal inscriptions, color registration across stamps, and printing faults that extend over several stamps. These attributes can affect rarity and value, since some utilities or errors are only visible on connected pieces.
Collecting and preservation
Collectors prefer unused, never-hinged blocks when possible, though used blocks with clear postmarks can also be desirable. Proper storage—mounts, archival pages, and minimal handling—helps retain gum, centering, and marginal inscriptions that contribute to a block's importance in a collection or study.
Notable distinctions
Blocks are distinct from singles not only in appearance but in philatelic significance. A corner plate block may carry a printer's control number that identifies the printing run; a gutter block can illustrate how sheets were laid out. For research, blocks supply evidence about production methods that singles cannot.