Whether he used a plumbiferous, or lead glaze; or a stanniferous, or tin glaze, we do not know.
It has long been a subject of doubt whether or not Egypt possessed the secret of stanniferous enamel.
A great deal has been said of the reflet mtallique and stanniferous enamel, and notably of the discovery of the latter in Italy.
The earthenware vessels with stanniferous enamel, called in Italy sgraffiato ware, have been attributed to Città di Castello.
All are transparent, with the exception of tin or stanniferous enamel.
