They included Tana ware as well as "Islamic white-glazed and early sgraffiato pottery.".    From Wordnik.com.  [Societies, Religion, and History: Central East Tanzanians and the World They Created, c. 200 BCE to 1800 CE] Reference

"Sgraffito" probably derives from the term "sgraffiato" an English pseudo-Italian word used in the nineteenth century.    From Wordnik.com.  [Interactive Dig Black Sea: Catalog of Artifacts] Reference

85 The sgraffiato ceramics are likely remnants of early trade initiated by emergent Swahili merchants.    From Wordnik.com.  [Societies, Religion, and History: Central East Tanzanians and the World They Created, c. 200 BCE to 1800 CE] Reference