Pliny the Elder gave attention to the large number of centers producing high quality wares in the Mediterrean Sea Basin. Some of them could be identified with workshops producing wares called as Terra sigillata. 

...maior pars hominum terrenis utitur vasis. Samia etiamnunc in esculentis laudantur. Retinent hanc nobilitatem et Arretium in Italia, et calicum tantum Surrentum, Hasta, Pollentia, in Hispania Saguntum, in Asia Pergamum. Habent  et Trallis ibi opera sua et in Italia Mutina...

Historia Naturalis (XXV 12<46>160)

Above mentioned citation was frequently quoted in the scientific literature. Some of mentioned by Pliny Italian centers, as Saguntum in Spain, could not be identified with workshops known from the archaeological evidence. Well known are manufactures located at Arretium and Pergamon instead. Tralles was the center of producing the Eastern sigillata B. According to J. W. Hayes, one of the greates experts of the ancient pottery, calices mentioned by Pliny were thin-walled beakers, commonly used from the 1st century B.C. to the 1st century A.D. The term "Samian ware" has taken on in the anglo-saxon scientific literature, however there is no archaeological evidence, that Terra sigillata was produced on Samos. There is a need to give the short characteristic of this cathegory of the ancient pottery to those, who come into contact with the name "Terra sigillata" first time. However this term has contemporary origin, its meaning contains various products, not only decorated by impressions of stamps (Latine- sigilla). Generally, the common feature of Terra sigillata wares is characteristic, red slip (glaze). It is present either on vessels named "plain wares" or on products ornamented by a relief decoration, impressed on wares with moulds-matrixes. Wares called as "plain" were often decorated by an applied ornament, "en barbotine" ornament, a roulette decoration or by imitations of the cut glass.

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