sellos

Sellos is a Spanish term with several related meanings. In everyday usage it most often refers to postage stamps (estampillas) placed on mail to indicate payment of a postage fee, but the singular sello can also denote a seal—an impression or mark used to authenticate documents or items.

Postage stamps are issued by national postal authorities. They are typically adhesive, affixed to envelopes or parcels, and canceled by mail processing machines or hand stamps to prevent reuse. Stamps display denomination values, geographic origin, and designs that may commemorate people, events, or cultural themes. Modern stamps often include security features and may be issued as self-adhesive labels or gummed issues. The study of stamps and postal history, philately, is a popular hobby with collectors seeking varieties such as rare issues, printing errors, and perforation differences.

As for seals, the term refers to marks pressed into wax, metal, or paper to seal a letter or document. Wax seals were common historically and often bore a coat of arms or emblem. Seals remain in ceremonial or authenticating contexts and in branding, where a printed or embossed seal is used on documents, packaging, or certificates. A related concept is the corporate seal, an imprint used to authorize company actions.

In some countries, stamps used to indicate taxes or duties are called revenue stamps. The plural sellos therefore encompasses stamps, and seals, and is a reminder of the linguistic overlap between securing authenticity and paying for postal services.