Grill

A grill is a pattern of tiny pyramid-shaped points embossed into a stamp. It is chiefly associated with United States stamps issued between 1867 and about 1871. The embossing was not decorative: it was a security measure intended to stop the reuse of stamps.

Why Grills Were Introduced

In the 1860s, the US Post Office worried that the public was removing cancellations from used stamps with chemicals and reusing them. Various inventors proposed solutions, and the adopted method was to emboss the stamps with a grid of small points. The embossing broke the paper fibres, so cancelling ink would sink into the paper and could not be washed out easily.

Grill Types

Catalogues classify grills by:

• Direction — whether the points project upwards (on the face) or downwards (from the back).
• Size — the dimensions of the grilled area, measured in millimetres or by counting the rows of points.

The grill types are designated by letters: A (covering the whole stamp), C, D, Z, E, F and others. Some are extremely rare on certain values. Correct identification requires careful measurement against catalogue data, and the Scott catalogue lists each grill type on each denomination as a separate number.

The 1-Cent Z Grill

The most famous grilled stamp is the 1-cent Z grill featuring Benjamin Franklin. Only two examples are recorded, making it one of the rarest United States stamps. One is held in the New York Public Library’s collection; the other has passed between prominent private collections.

Fakes and Pitfalls

Because grilled stamps can be worth many times more than ungrilled copies of the same design, fake grills have been pressed into ungrilled stamps. Genuine grills have characteristic sharpness and spacing; fakes may be too shallow, too regular or the wrong size. Partial or faint grills are also common and can be hard to classify. Expert certification is strongly recommended for scarce grill types.

Why Grills Ended

The process was slow, damaged the paper, and caused problems in separating and handling sheets. Grilling was phased out around 1870–1871, and later security relied on other approaches such as special inks and papers.