terra sigillata

Noun

terra sigillata (uncountable)

1. A type of astringent earth or clay originally from the Greek islands, formerly used as a medicine and antidote.
   • Terra sigillata (sealed earth) was a greasy clay, containing silica, alumina, chalk, magnesia and oxide of iron, found on the Greek islands of Lemnos, Melos and Samos.1997, Roy Porter, The Greatest Benefit to Mankind, Folio Society, published 2016, page 77
2. A type of fine, red Roman pottery made from the first to the third centuries AD in Gaul.
3. (pottery) A type of fine clay slip produced by mixing clay-water mixture with deflocculant and decanting the resulting water.
   • Terra sigillata, or ‘terra sig’ for short, is made by mixing a suitable clay with water and a deflocculant and leaving it to stand until the heavier particles of clay settle out.2024, Sumi von Dassow, “Terra Sigillata 101: How to Make, Apply, and Troubleshoot Terra Sig”, in Ceramic Arts Network Daily, retrieved 23 Aug 2024