OFFICIAL16 What is the lecture mainly about?

[00:00.00]Narrator: Listen to part of a lecture in an art history class.
[00:05.95]Male professor: Ok, now, um, a, a sort of paradigmatic art form of the Middle Ages was stained glass art. [00:14.46]Stained glass, of course, is, is simply glass that has been colored and uh cut into pieces and reassembled to form a picture or, or, decorative design.
[00:24.68]To truly experience the beauty of this decorative glass, you, you should see it with light passing through it, uh, especially sunlight. Which is why stained glass is usually used for windows, [00:37.26]but of course it has other uses, especially nowadays.[00:41.22]Um anyway the art of making stained glass windows developed in Europe uh during the Middle Ages and was closely related to church building.
[00:51.67]In the uh early 1100s, uh, a church–building method was developed that reduced the stress on the walls, so more space could be used for window openings—allowing for large and, and quite elaborate window designs.[01:09.08]Uh back then the artists made their own glass, but first they came up with a design. [01:16.17]Uh paper was scarce and expensive, so, so typically they drew the design onto uh a white tabletop. [01:24.17]They’d draw the principal outline, but also outline the shape of each piece of glass to be used and uh indicate its color.
[01:34.82]Now, uh, in the window itself, the pieces of glass would be held together by strips of lead, so, um, so in the drawing, the uh artist would also indicate the location of the lead strips. [01:48.47]Uh then you could put uh a big piece of glass on the tabletop and and see the design right through it, and use it to uh to guide the cutting of the glass into smaller pieces.[02:01.81]Male student: And the lead that was just to hold the pieces of glass together?
[02:05.07]Male professor: Well, uh, lead is strong and, and flexible so it is ideal for joining pieces of glass cut in different shapes and sizes. [02:13.57]Uh but up to the fifteenth century, the, uh the lead strips also helped create the design—[02:19.49]they were worked into the window as, as part of the composition. [02:23.67]Um they were used to outline figures, to, to show boundaries—just like you might use solid lines in a pencil drawing.[02:32.87]Male student: How did they get the color…[02:34.23]I mean how did they color the glass?[02:36.95]Male professor: Well, up until the sixteenth century uh stained glass was colored during the glassmaking process itself. [02:44.39]Uh you got specific colors by adding metallic compounds to the other glassmaking ingredients. [02:52.33]So, uh if you wanted red, you, you added copper, [02:56.46]if, if you wanted green, you added iron. [02:59.14]You just added these compounds to the other ingredients that the glass was made of.[03:04.69]Female student: So each piece of glass is just one color?
[03:07.72]Male professor: Yes, um, at least up until the sixteenth century. [03:10.85]uh then they started, um, you started to get painted glass. [03:16.44]Uh painted glass windows are still referred to as “stained glass” but the colors were actually painted directly onto clear glass, after the glass was made. [03:28.61]So um with this kind of stained glass, you could uh paint a piece of glass with more than one color.
[03:35.98]Female student: And with painted glass, they still used the lead strips?
[03:39.38]Male professor: Yes, uh, with really large windows, it took more than one piece of glass, so you still needed lead strips to hold the pieces together. [03:49.67]But the painters actually tried to hide them. So it was different from before, when the lead strips were part of the design. And, and it’s different because with painted glass the idea of light coming through to create the uh, the magical effect wasn’t the focus anymore…
[04:09.94]the paint work was.[04:17.15]in, in the 19th century people started using them in private houses and, and public buildings. [04:24.21]Unfortunately many of the original, stained glass windows were thought to be old–fashioned and…and they were actually destroyed, replaced by painted glass.[04:37.47]Female student: They actually broke them? [04:39.23] That showed good judgment, real foresight, didn’t it?
[04:42.98]Male professor: Yes, if only they had known… [04:46.35]um and it's not just that old stained glass is really valuable today; we lost possibly great artwork. [04:54.38]Uh but luckily there was a revival of the early techniques in the mid–1800s, and, and artists went back to creating colored glass and using the lead strips in their designs. [05:08.21]The effects are, are much more beautiful.[05:12.21]In the nineteenth century uh Louis Tiffany came up with methods to create beautiful effects uh without having to paint the glass. [05:22.17]He layered pieces of glass and used thin copper strips instead of lead. Which let him make these, these really intricate, flowery designs for stained glass. Which he used in, in lamp shades—[05:37.16]you've heard of Tiffany lamp shades, right? [05:40.05]These of course took advantage of the new innovation of electric lighting—
[05:44.92]e–electric lightbulbs don't give quite the same effect as sunlight streaming through stained glass, but it's close. [05:53.33]So uh layered glass, Tiffany glass, became very popular and still is today. [06:00.56]So um, let's look at some examples of different types of stained glass from each era.