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 Glass Question at our Rakow Research Library.

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Gold Leaf
Video

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.

Tumbler
Video

Here is the most sophisticated glassblowing process used to make the simplest of all forms: a cylindrical tumbler. The second most important tool after the invention of the blowpipe, the soffietta is used to make the work easier with better results.

Pressing into a Mold
Video

While the mechanization of pressing glass into a mold is a 19th-century American development, the basic process was known almost from the beginning of glassmaking. Here the process is shown in its simplest form, using an open-faced mold and molten glass.

Sandblasting
Video

Here is the easiest, most modern way of decorating the surface of a piece of glass. A young child can sandblast competently! In the hands of a sophisticated artist, though, effects both subtle and dramatic are possible.

Cutting Glass with a Diamond Saw
Video

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.

Grinding Glass
Video

Grinding is a process of removal by abrasion. People were grinding stone tools long before the discovery of glassmaking.

Spiral Thread and Handle on Roman Bottle
Video

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!

Lathe Cutting
Video

Here is everything you might want to know about how cut glass gets its decoration. Battuto cutting, much loved by contemporary Venetian glass artists and their followers, is also shown. Incredibly ancient in origin, the process is still widely appealing.

Practical Applications of Tension in Glass
Video

"Annealed glass," "safety glass," "tempered glass"... Confused? Learn the differences through these Glassbreaking Demos.

Ice Glass
Video

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?

Hand Sanding Glass
Video

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.

Dremel Tool
Video

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.

Raw Materials of Glass
Video

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.

Prince Rupert's Drop
Video

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.

Optic Molding
Video

This technique was invented by Roman glassworkers. It was indispensable in glasshouses of the Middle Ages and flourished in Venice. Also known as dip molding, it remains popular today.

Murrine Use
Video

Once murrine canes are cut into thin slices, they can be fused and slumped, flameworked, or blown. Here, murrine canes are used in demonstrations of a Roman period process and a Renaissance Venetian process.

Ladle Casting
Video

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!

Cutting Glass
Video

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.

Flameworked Beads
Video

Flameworking (sometimes called "lampworking") is the process of directing a flame onto a piece of glass in order to create form or decoration. Beads were likely among the first glass objects to be made by flameworking.

Chunk Casting
Video

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.

Coloring Objects
Video

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.

Bowl with Roman Foot and Folded Edge
Video

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.

Pâte de Verre
Video

This is another casting technique that—like glassblowing—only works with glass. Whereas glassblowing was invented about 50 BC, pâte de verre is a process invented in France in the 19th century. It allows subtle gradations of color, possible with no other glassworking process.

Flameworked Vessels
Video

Beginning in the 1800s, glassworkers used flameworking to make vessels considerably larger than previously possible. Bigger and more sophisticated torches allowed the increase in scale, while retaining the flameworker's ability to create minute details.

Cracking Off
Video

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.

Cane Making
Video

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.

Building a Goblet on a Blowpipe
Video

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.

Fusing and Slumping
Video

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.

Learn About Glass Enameling
Video

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.

Solder vs. Glass Rod
Video

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.

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