Glass painting
Glass painting is the art of drawing and shading on glass with vitreous paint, which is then fired so that it becomes part of the glass. It is the craft that turns coloured glass into pictures: faces, hands, hair, drapery, lettering and detail are all painted, and the lead lines support the drawing.
The painter uses brushes and other tools to apply a strong outline, then a wash of thinner paint to give tone, and removes paint from the wash to leave highlights. Silver stain adds yellow on the other side. Each layer is fired, and complex pieces may be fired three or four times.
Painting on glass was one of the major medieval crafts and continues today, in the studios that restore old windows and make new ones.