Vitreous enamel, also called porcelain enamel, is a material made by fusing powdered glass to a substrate by firing, usually between 750 and 850 °C. The powder melts, flows, and then hardens to a smooth, durable vitreous coating. The word comes from the Latin vitreum, meaning "glass"

Azulejosconstitute a major aspect ofPortuguese architectureto this day and are fixtures of buildings across Portugal and its former territories. Many azulejos chronicle major historical and cultural aspects ofPortuguese history

The wordazulejo(as well as theLigurianlaggion[4]) is derived from theArabicالزليج(al-zillīj):zellij, meaning "polished stone"