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What IS Terra Sigillata

Terra sigillata is a slip made of super fine particles of clay that will take a burnish. Its rich, reddish hue is due to a concentration of iron oxide in the clay. "Terra sigillata" is Latin for” sealed earth", (not from the burnishing, but from its origins). The original terra sigillata clays, thought to have medicinal qualities, were dug on the island of Lemnos (located in the Northern Aegean opposite the Dardanelles) August 6th of each year. The clay was put into containers and thus the name.


Others believe that the term is a misnomer used by scholars stemming from the word “sigil” or “seal”, owing to the relief work on some of the original pieces, called Barbotine. Pieces finished with this red slip are also generally known as "Samian Ware".
This ultra fine slip was also used by earlier cultures such as the Minoans, Myceneans and later by the classical Greeks, but is mostly seen in colors such as cream or buff, white and black rather than the red iron oxide color seen in Roman pottery. Pots finished in this way span from the Late Geometric or Hellenistic Period, about 750-BC, to the Late Roman Imperial Period, about AD 200; the finest Roman examples were made from 30BC to 200AD. Today, fine red terra sigillata slip is used on some traditional Central Native American pottery.


The dry, “greenware” is first burnished to sheen with a stone. Terra Sigillata “slip” (refined clay) is then applied in several layers to coat the dry, unfired, burnished clay. Each piece is then individually hand polished with each successive coat using a piece of chamois leather. The piece is fired once at 1620 degrees F /880 C. Pieces with clear glaze inside are fired twice at a higher temperature.

 

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