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Valor de los sellos

Bloques de plancha: qué son y cuánto valen

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Un bloque de plancha es un bloque de sellos todavía unido al margen del pliego que lleva el número de la plancha de impresión. Los bloques de plancha estadounidenses modernos suelen venderse por su valor facial, mientras que los de la época clásica, sobre todo anteriores a 1940 y en buen estado, pueden valer varias veces lo que los mismos sellos sueltos.

Datos clave

Qué es
Un bloque de sellos con el margen que muestra el número de plancha
Formato moderno (EE. UU.)
Normalmente un bloque de 4, con el número en el margen de la esquina
Formato clásico
A menudo bloques de 6, y mayores en algunas emisiones tempranas
Valor moderno
En torno al valor facial. Se guardaron en cantidad
Valor clásico
Un sobreprecio sobre los sellos sueltos, a veces grande
Estado
Margen intacto, dentado completo y sin fijasellos es lo que más importa

What is a plate block?

It's a block of stamps that still has the sheet margin attached, with the plate number printed on that margin. The number identifies the printing plate used, which is why collectors keep the block intact.

Sheets were printed from numbered plates, and the number appears in the selvage, the blank paper around the stamps. Tear the selvage off and it's an ordinary block. Keep it, and it's a plate block, a collecting speciality of its own, particularly in the United States.

Other margin markings are collected the same way: copyright blocks, “Mr. ZIP” blocks and, on coils, plate number singles or strips cut from the roll.

How do I know if I have a plate block?

Look at the margin attached to the block. If it shows a number, usually small and printed near the corner, and the stamps are still joined to it, you have a plate block.

  • Modern US issues: a block of 4 stamps with the plate number in the corner selvage.
  • Older flat-plate issues: the standard collecting unit is often a block of 6, and sometimes larger.
  • Position matters: the selvage should be the one bearing the number, not a blank margin from elsewhere on the sheet.
  • Don't trim it. Cutting the selvage down to “tidy” it removes the point of the block.

What are plate blocks worth?

Modern plate blocks usually sell for around the face value of the stamps in them. Classic plate blocks, especially from before about 1940, can be worth several times the price of the same stamps as singles.

General patterns. The specific issue and condition decide the value.
EraTypical plate block value
Classic US issues to about 1930A significant premium over singles, when sound and well centered
1930s–1950sModest premium on better issues, near face value on common ones
1960s onwardUsually about face value. Very large numbers were saved
Errors and scarce varietiesCan be worth far more, especially with the number attached

The pattern is the same one that governs the rest of the hobby: things collectors deliberately saved in bulk stay cheap. See commemorative stamps value.

What condition issues matter for plate blocks?

Centering across all the stamps, intact perforations between them, clean and uncreased selvage, and gum that has never been hinged. A hinge mark on the selvage alone reduces the price.

  • Never hinged is the standard for modern plate blocks. Hinging, even on the margin, cuts value.
  • Separation matters: pulled perforations between two stamps devalue the whole block.
  • Selvage damage, such as creases, tears and mounting marks, counts against it.
  • Even centering across four or six stamps is harder to find than on a single, which is part of the appeal.

See stamp condition grades for the terms dealers use when describing blocks.

Should I break a plate block into singles?

Usually not. A classic plate block is worth more intact than as separate stamps, and breaking it is irreversible. For common modern blocks it makes little difference, since both are worth about face value.

If you're not sure which you have, treat the block as intact until it's been identified. The same rule applies to other multiples: pairs proving an imperforate error, blocks showing a plate flaw, and se-tenant strips are all worth more whole. See error stamps worth money.

What are copyright blocks, ZIP blocks and plate number coils?

They're the other margin-marking collectables. Copyright blocks show the postal service's copyright notice, ZIP blocks show the “Mr. ZIP” reminder, and plate number coils are coil stamps carrying a small plate number on the stamp itself.

TypeWhat to look for
Copyright blockSelvage carrying the copyright notice, collected as a block of four
ZIP blockSelvage with the “Mr. ZIP” character or ZIP code reminder
Plate number coil (PNC)A tiny plate number printed at the bottom of one stamp in a coil roll
Plate number singleA single stamp cut from a sheet so the number stays attached

Most of these sell for around face value, with the same exception as plate blocks: scarce plate numbers and short-run printings carry a premium, and specialists track exactly which numbers are hard to find. If you're sorting a modern accumulation, don't tear margins off anything until you know which markings it carries.

Paso a paso

How to check a plate block with StampGo

Start by identifying the stamp in the block. Once you know the issue and its era, the premium question answers itself.

  1. 1

    Scan one stamp in the block

    Tap Scan Now and photograph a single stamp from the block, filling the frame, without separating anything.

    Escáner de StampGo enfocando un sello estadounidense de 1 centavo de Benjamin Franklin, con los botones de flash, disparador y galería
  2. 2

    Check the issue and year

    A pre-1940 issue with a meaningful reference price is worth researching as a plate block. A modern one usually isn't.

    Resultado de StampGo para el sello de 1 centavo de Benjamin Franklin de 1857, con un precio de referencia de 10 a 100 dólares y un índice de rareza de 3 sobre 10
  3. 3

    Log it as a block

    Save the stamp to your collection and note in your own records that you hold it as a plate block, with the plate number.

    Pantalla Mi colección de StampGo con un total de 196,13 dólares en cuatro sellos, entre ellos un Curtiss Jenny de 24 centavos y un Penny Lilac
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Preguntas frecuentes

¿Qué diferencia hay entre un bloque de plancha y un bloque de esquina?

Un bloque de esquina es simplemente un bloque tomado de la esquina de un pliego. Solo es bloque de plancha si el margen unido lleva el número de plancha.

¿También se coleccionan los bloques de plancha canadienses?

Sí. Las emisiones canadienses se coleccionan en bloques de plancha de cada esquina del pliego, y catálogos especializados como Unitrade los recogen por separado.

¿Vale un bloque de plancha más que cuatro sellos sueltos?

En las emisiones clásicas, normalmente sí. En las modernas, rara vez: ambos suelen valer aproximadamente su valor facial.

¿El número de plancha cambia el valor?

A veces. En emisiones donde algunas planchas tuvieron tiradas mucho más cortas, los bloques de esas planchas escasas alcanzan un sobreprecio. Es terreno de especialistas, y los catálogos detallan las diferencias.

¿Debo guardar los bloques de plancha en monturas?

Sí. Usa una montura lo bastante grande para que el bloque y su margen queden planos, sin presionar el dentado. No pongas nunca fijasellos a un bloque de plancha moderno: una marca en el margen ya reduce lo que pagará un comprador.

Fuentes

  1. Plate block (Wikipedia)
  2. American Philatelic Society: Stamp vocabulary
  3. Linn's Stamp News: What to look for when you're looking for stamps
  4. Scott catalogue (Wikipedia)

Descubre hoy mismo cuánto valen tus sellos

Haz una foto y StampGo te muestra el país, el año, la rareza y un valor estimado en segundos. Descarga gratuita para iOS y Android.

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