Stained glass, also known as polychrome stained glass, are compositions that are made up of colored glass. These can represent any scene or motif, but, in general, they are used as decoration in churches, giving life to some of the most important actions seen in the sacred scriptures. The glasses used, according to the traditional artisan process, are extracted from the desert; later they are painted or covered with enamels, and, once arranged with the desired shape, they will be assembled with lead rods. The word is a loan from the French “vitral”, which in turn comes from the Latin “vitrum”, with the addition of the suffix –ail.
Stained glass windows were already quite common in Romanesque churches. However, its heyday is during the predominance of the Gothic style, so its use was extended and normalized. These used to have an appearance similar to that of a mosaic and a large number of colors were used to represent religious motifs, with the exception of black and gray, because they were used in the outlines. Around the sixteenth century, any colorless glass was available, to which enamels were applied, like a canvas. In the 18th century, the stained glass windows studied from that time are scarce, since almost all are imitations of previously made works.
The stained glass creation process was quite systematic, consisting of cutting a pattern, pigmenting the pieces and firing in the oven. The glass was obtained from the mixture of silica, potash and lime; pigments, on the other hand, are nothing more than mineral oxides. These, once finished, were intended to serve as decorations in churches, usually as windows.
