Block

A block is a group of stamps still joined together in at least two rows and two columns. The most familiar form is the block of four — two stamps across and two down — but blocks of six, eight, ten or more are also collected. Blocks are one type of multiple, the general term for any group of stamps that remain attached as printed.

Types of Multiple

• Pair — two joined stamps, side by side (horizontal pair) or one above the other (vertical pair).
• Strip — three or more stamps in a single row or column.
• Block — at least two rows and two columns.

Special Kinds of Block

Plate blocks (or plate number blocks) include the sheet margin with the printing plate number. They are a standard collecting unit in the United States, where collectors traditionally save a block of four or six with the plate number attached.

Corner blocks come from a corner of the sheet and include two margins. Corner blocks sometimes carry printing dates, sheet numbers or printer’s imprints.

Imprint blocks carry the name of the printer in the margin.

Gutter blocks include the gutter between two panes.

Se-tenant blocks contain stamps of different designs printed together — see se-tenant.

Why Blocks Are Collected

Blocks show how stamps were printed and laid out on the sheet. They can reveal plate flaws that repeat in fixed positions, guide lines, and varieties that only make sense in context. For classic 19th-century issues, used blocks are especially scarce: most mail needed only a single stamp, so large used multiples on or off cover are rare and valuable.

Blocks also help authenticate stamps. A variety or error is much more convincing when shown alongside normal stamps in the same block.

Care and Storage

Blocks are prone to separation along the perforations. Store them flat in mounts or stockbook strips large enough to hold them without folding, and avoid hinging across perforations. If a block must be hinged, use several hinges spread across the stamps to support the weight evenly.