Seal (device): marks, instruments and their uses

Parts and appearance

Seals typically consist of a matrix (the carved or engraved surface), an impression or cast made from that matrix, and sometimes a legend or inscription identifying the issuer. Materials include wax, lead, paper, metal and modern polymers. Designs often combine text, heraldry, religious or symbolic imagery and decorative borders. The same device can produce either a raised (intaglio) or recessed (relief) impression depending on technique.

History and development

The practice of sealing has ancient roots: cylinder seals and impressed tokens appear in Mesopotamia and Egypt, while signet rings and stamped seals were common in classical and medieval societies. The English word derives from Latin sigillum. Over centuries seals evolved from personal authentication tools to official state devices; they were essential to legal and diplomatic practice before widespread literacy and standardized signatures.

Functions and examples

Seals serve several practical and symbolic roles: verifying identity or authority, securing correspondence or containers against tampering, endorsing legal acts and conveying status. Examples include notarial seals, corporate embossers, heraldic great seals on treaties, and simple envelope seals on private letters. Today physical seals coexist with digital and electronic seals used to protect electronic records.

Types and notable distinctions

• Signet ring: a personal seal worn and used to press a device into wax.
• Pendant seal: hung from a document by cords or ribbons.
• Embosser: creates raised impressions on paper without wax.
• State or great seal: used by governments to authenticate legislation and official acts.

Forgery and tampering have long been concerns, prompting forensic examination of impressions and the growth of specialized study. The academic discipline that investigates seals, their manufacture, use and historical context, is called sigillography. Collecting and conserving seals is important for archival and historical research because seals often preserve iconography and administrative details absent from plain text.