Ownership of documents, jars of oil and wine, and other precious commodities was indicated by means of a clay seal. Papyrus rolls were each folded in two and tied with a thread which was fastened with a clay seal, and the owner's special impression or seal was marked on the lump of clay that secured jar stoppers or box lids.
Various devices were used as seals including scarabs (set in rings or pendants), as well as flat or cylinder seals. On the latter, the design or owner's title was cut on to the outer surface, and when the cylinder was rolled over wet clay, the impression was transferred to the clay.
Biographical Dictionary of Ancient Egypt by Rosalie and Antony E. David
Ancient Egypt. A Reference Guide. EdwART. 2011.