Glasses will dissolve a wide variety of different materials such as the oxides of chromium, cobalt, copper, iron, manganese and nickel to produce a rainbow of colours. Each element of the coloured components in this Medieval Stained Glass Window (11th Century, Augsburg, Germany) consists of an individually produced coloured glass sheet cut to the required shape any held in place by lead cames. In this window enamelling with black stain was used to add fine detail.
Later people learned how to use silver stains to produce local areas on clear sheets that were coloured yellow or orange. This same basic technology of ion exchange is now used to strengthen fine objects such as wine glasses and to produce thin channels in the surface of glass sheets that can guide light, just as optical fibres do.