All About Glass
All About Glass
This is your resource for exploring various topics in glass: delve deeper with this collection of articles, multimedia, and virtual books all about glass. Content is frequently added to the area, so check back for new items. If you have a topic you'd like to see covered, send us your suggestion. If you have a specific question, Ask a Librarian at our Rakow Research Library.
It doesn't get more complicated than this! Here is the Renaissance Venetian way of making an ornate dragon-stemmed goblet. Pre-made parts are attached using small bits of molten glass as "glue."
A spectacular demonstration unique to glassblowing, ice glass was widely popular in Low Country cities like Amsterdam during the 17th century. Did the abundant canals of Amsterdam and of Venice, where the process was invented, inspire this watery idea?
Decoration in glassblowing at the furnace doesn't get more basic than this. Although it looks easy, glassblowing students struggle for weeks with every step forward!
Everyone knows that wood can be sanded to change its finish; surprisingly, so can glass. Specialized grinding blocks coated with industrial diamonds are best, but regular sandpaper works too.
The next time you're in the dentist's chair, know that the grinding you hear—and feel—could also be taking place on a piece of glass! The very same tool can be used by artists to create beautiful engraved effects.
Learn about how glass is colored with Corning Museum of Glass experts. Colored glass is made by adding small amounts of metal oxides to the batch.
Some of the first glassblowers working in Italy—perhaps as early as 30 BC—made blanks for craftspeople accustomed to decorating hardstone objects. The glassblowing process required two contrasting glasses, usually blue and white.
Essentially the same as lathe cutting, the engraving lathe is generally used for small-scale projects often involving the creation of extremely fine details, such as the eyelashes on a portrait.
See and understand the magical process of making glass from simple materials, by using great heat. Until the most recent times, glassmaking was a closely guarded secret passed on within workshops or even families from one generation to the next, often over hundreds of years.
"Annealed glass," "safety glass," "tempered glass"...Confused? Learn the differences through these Glass-breaking Demos.
Grinding is a process of removal by abrasion. People were grinding stone tools long before the discovery of glassmaking.
Throughout glass history, workers have needed to saw pieces of glass cleanly. Using string and gritty mud-like slurry, ancient Egyptians and Greeks, for example, spent days accomplishing what the modern electric diamond saw does in seconds.
Gold decoration has been popular since Egyptian times. Roman, Byzantine, and Islamic workshops also used it frequently. Beginning in the Renaissance, gold decoration became an indispensable part of the Venetian style.
Artists have proven that glass as a medium for sculpture is virtually without limits. Among hot-working processes, flameworking allows the greatest detail and the smallest scale. Surprisingly though, it can also be used to create sculpture large enough to fill rooms.
Hot-working processes used to form a glass object—glassblowing for example—must be followed by a very gradual cooling period called annealing. See what happens when an object is not properly annealed and learn why it breaks.
See what really sets glass apart from metal and then begin to understand why humans have invented such odd ways of shaping it while hot: core-forming, fusing, slumping, and—oddest of all—glassblowing.
A technique unique to glass, air twist requires very high quality material for success. When sparkling lead crystal became common in 18th-century England, the air twist technique spread rapidly.
By about AD 20, Roman workers had discovered that a bubble of molten glass could be lowered into a mold and then further inflated to fill the mold. In this way, the full-size vessel, complete with elaborate decoration, was made almost instantly.
Molten glass can be cast by a method virtually identical to that used for casting metal. Here, molten glass at 2300 degrees Fahrenheit is ladled into a mold made of sand. The process is relatively easy as hot glassworking processes go...but hot!
Don't try this at home! A classic demonstration involving exploding glass: it spectacularly shows both the great strength and vulnerability of glass that has been rapidly cooled from the molten state.
While glass canes can be used alone, for example as stirring rods, usually they are incorporated in vessels or sculpture. An infinite variety of decoration is possible. Here we see two examples that are intended to be viewed from the side.
Here is virtuoso Venetian-style glassblowing "without a net." One mistake and all is lost! Where "making a goblet from parts" allows mistakes to be isolated and destroyed, this process moves relentlessly forward, allowing no retakes.
Popular among glass artists today, as it was in the golden age of Greece and the Roman Empire, this technique softens and shapes glass in a kiln. Various preparatory steps are shown in the making of a contemporary sculpture.
It could have been so simple...but it wasn't! Until recent times (about 1800), permanent enamels had to be fired on glass vessels by an amazingly laborious process, shown here. Today, the process really is as easy as it looks.
Five different methods of using colored glass are demonstrated; some produce a uniformly colored object, others a splotchy or mottled effect. Glass artists today use whatever method best suits their aesthetic choices.
Roman glassworkers, tirelessly creative and inventive, were fond of folding and manipulating inflated glass in a variety of ways for different purposes. Two of their characteristic structures—both functional and beautiful—are demonstrated.
As if glassblowing wasn't fast enough—it takes under three minutes to make a Roman bottle—cracking-off made the process even faster. This technique was well known by AD 20 or so, and cut the manufacturing time of simple tumblers in half.
Chunks of glass are placed in a mold, then heated in a kiln until the glass softens and flows downward to gradually fill the mold. Popular with contemporary artists, this method avoids the need for a giant melting furnace filled with molten glass.
Cutting thin sheet glass is almost as easy as it looks in this video clip...but not quite! Curves really are much trickier than straight lines. The process shown would have been completely familiar to medieval window glaziers.
Learn about flameworking with Corning Museum of Glass experts. Flameworking is the technique of taking glass rods or tubes and heating them in a concentrated flame until they become soft.