CAPTURING MAGIC THE MAKING OF STAINED GLASS SD

Welcome to the wonderful world of stained glass. In this short film we're going to look at how beautiful windows were created hundreds of years ago and we'll be visiting craftsmen and women who are still making stained glass windows today. Since the beginning of time light has been thought of as divine and for a pilgrim visiting a medieval building such as Ely Cathedral this would have been a profoundly moving experience. In medieval times windows like these were very expensive. Often commissioned by kings, bishops or other wealthy donors stained glass windows became the perfect means for illustrating stories and figures from the bible. So how was glass discovered? Glass is a product of molten sand which comes from a hard rock called silica It is said that the first glass was discovered by accident in Syria over 5,000 years ago when some Phoenician sailors were cooking their supper over a fire. They balanced their pots on lumps of salt and in the morning they found the sand on the riverbank melted by the intense heat of the fire had mixed with the salt and wood ash and turned to glass. The uses of glass evolved over the next 2,000 years but it was the introduction of the blowing iron by the Romans in about 40 BCE that completely transformed glass production. Much larger vessels could be made in any number of shapes and by blowing glass into balloon-like cylinders and splitting open the balloons even thinner sheets of glass were produced. So when did stained glass windows first appear in English buildings? Stained glass window making reached its peak between 1100 and 1500. The techniques were a close-kept secret but in the early 12th century a monk called Theophilus began to compile a handbook of all the processes, colouring and blowing glass, mixing paint and putting the windows together. Since then remarkably techniques have hardly changed. Glass is traditionally coloured by adding precious metals such as copper, cobalt, iron and gold. In England making coloured glass didn't take off until the 1800s but now there is only one factory left in the United Kingdom blowing hot glass for stained glass windows. The glassblowers have to be very strong and agile, every twist, turn and swing is a critical part of the process. It's a skill that has changed little since Roman times. Once blown the cylinders of glass are cut open and flattened using a block of dampened wood. Every window has a design. The artist sketches out the window to scale on large pieces of paper. In medieval times when paper was scarce the design was drawn on a whitewashed board. Using this scale drawing the pieces of glass are then cut to size. In medieval times glass was first cut using a hot bar of iron. Nowadays a small wheel cutter is used and then the glass is cleaned up around the edges with a grozing iron. The glass is often decorated with paint. Glass paint is made of powdered glass mixed with an oxide which colours it brown black. Glass painting requires great skill and years of practice to perfect. Brushes made from animal hair such as donkey, squirrel or badger are often handmade and are selected by the artist who wants to create a particular effect. At the beginning of the 14th century a new way of colouring glass was discovered using a substance called silver stain. When applied to clear glass and fired in the kiln it stains the glass a beautiful yellow colour. It's been used ever since to highlight features such as crowns, hair, angels wings and architecture in stained glass. After painting and staining the glass is fired in a kiln to fuse the paint to the glass surface. Medieval kilns were built in the open air and heated by charcoal. Getting the fire to exactly the right temperature around 650 degrees centigrade was critical. Each firing took two and a half days. Today we can fire the glass in a gas-fired kiln in 40 minutes. Lead is the perfect material for making out stained glass windows as it is soft easy to cut and rust proof. Sadly there is very little small-scale production of lead casting left in England. The lead is cast in a mould and then passed through a lead mill to produce strips called canes. A lead cane has a groove on either side into which the edges of the glass fit. Where lead joints meet they are fixed with a solder, a mixture of tin and lead. Finally the completed panel is made watertight with a black putty and is then ready for fitting. The panels are attached to bars of iron or bronze in the window opening. Copper or lead ties are soldered to the panels to make sure they are firmly fixed. Coloured glass never fades. This doesn't mean though that the glass is everlasting. Exposure to weather, pollution, gunshots and even low-flying birds can damage windows over time. New techniques have extended the possibilities for both the professional and amateur stained glass artist but there is still so much to do in the conservation and repair of historic stained glass. Many highly skilled artists and craftsmen are involved in making stained glass. We have seen the ancient techniques of the glassblower and the lead maker, the skill of the glass painter and the important role of the 21st century conservator. Today we can still be transfixed by the amazing beauty of stained glass not only in churches but in public buildings, museums and private houses. Stained glass windows capture and transform light in truly magical ways.