Stain Glass of Middle Ages
Mural paintings were gradually replaced in favor of stain glass. This transformation was helped in a large part to the new Gothic Architectural style which allowed for large stain glass windows in the Cathedrals (see Gothic Architecture for more). The illustrated manuscripts provided the design ideas for many of the windows. Colored glass would be cut by a hot iron. Then details would be painted on the glass with black enamel paint. The glass would be heated to bake the enamel onto the glass. The pieces would then be put together with a strip of lead to hold the glass pieces together. Many of the windows were in 12 large sections which may have represented the 12 apostles.