A material made by fusing powdered glass to a substrate (usually metal) by firing, usually between 750 and 850 °C (1,380 and 1,560 °F). where the powder melts, flows, and then hardens to a smooth, durable vitreous coating.
1950 October, “Notes and News: Renaming of Stations, L.M.R.”, in Railway Magazine, page 713:
The new name signs will be of modern design in vitreous enamel, and consist of white Gill Sans letters on a maroon background.
