Tiffany glass

History of Tiffany Glass

Tiffany glass is the generic name used to describe the many and varied types of glass developed and produced by Louis Comfort Tiffany, (1848-1933), one of the most famous stained glass artists of the United States; he was remembered not only for his windows but for decorative glass objects as well, in particular the so-called Tiffany lamps.

Tiffany was an interior designer, and in 1878 his interest turned towards the creation of stained glass, when he opened his own studio and glass foundry because he was unable to find the types of glass that he desired in interior decoration.

Tiffany Glass

Most people think of Tiffany glass as decorative bronze lamps with intricate multicolored, stained-glass shades, but it actually includes other glass products, including solid color windows, painted art glass shades and lamps, and flat and pressed glass. Tiffany glass pieces were incorporated into homes, most notably in lamp and window construction. The glass work was used in the homes of the wealthy, but also in public buildings.

Tiffany glass not only incorporates the color into the glass, but also tonal variations and texture, as well as use tonal variations to suggest depth. The pieces of glass were not evenly colored but were pieces of opalescent window glass made by combining and manipulating several colors to create an unprecedented range of hues and three-dimensional effects. Thus the tiffany windows look like paintings, which were therefore in great demand.

The Preston Bradley Hall dome put in place in Chicago's first public library in 1897 features more than 1,000 square feet of Tiffany glass. (Preston Bradley Hall is now home to the Chicago Cultural Center.)

Types of Tiffany glass

1. Opalescent glass

Opalescent glass is commonly used to describe glass where more than one color is present, being fused during the manufacture, as against flashed glass in which two colors may be laminated, or silver stained glass where a solution of silver nitrate is superficially applied, turning red glass to orange and blue glass to green. Some opalescent glass was used by several stained glass studios in England.

Opalescent glass is made with a combination of white glass and a cathedral color. The opacity of this type of glass is in relation to the amount of white glass used in its creation. Dense opal base glass uses a higher consistency of white glass than light opal base glass. Because of this change in mixtures, dense opal base glass is much more opaque than light opal base glasses.

Opalescent glass radiates especially deep, vibrant hues to achieve pictorial effects of unsurpassed beauty. This stunning stained glass piece features transparent enamels, silk-screened and kiln-fired on hand-rolled glass.

Opalescent glass is made in a number of ways, including as a single colour; with the pigments that give the glass a streaky, mottled, or cloudy appearance; and with or without a surface texture. It can be both a most beautiful and challenging glass with which to work. This is because the pigments are mixed into opalescent glass by hand during manufacture, with the result that the color patterns and tones in the glass are never exactly the same in any two sheets.

Opalescent glass has one characteristic that transparent glass does not: namely, that it can be seen in both transmitted and reflected light. Opalescent glass has color impregnated into it to the extent that the pigmentation is visible by light rays reflecting off it. It can be seen as well as seen through.

2. Favrile Glass

Favrile glass often has a distinctive characteristic that is common in some glass from Classical antiquity: it possesses a superficial iridescence. This iridescence causes the surface to shimmer, but also causes a degree of opacity. This iridescent effect of the glass was obtained by mixing different colors of glass together while hot. Favrile is different from other iridescent glasses because its color is not just on the surface, but imbedded in the glass.

Some of the distinguishing colors in Favrile glass includes "Gold Lustre", Samian Red"," Mazarin Blue", "Tel-al-amana" (or Turquoise Blue), and Aquamarine. Favrile was the first art glass to be used in stained-glass windows, as Tiffany first thought of the idea of making patterns in windows based shapes and colors.

3. Streamer Glass

Streamer glass refers to a sheet of glass with a pattern of glass strings affixed to its surface. Tiffany made use of such textured glass to represent, for example, twigs, branches and grass.

Streamers are prepared from very hot molten glass, gathered at the end of a punty (pontil) that is rapidly swung back and forth and stretched into long, thin strings that rapidly cool and harden. These hand-stretched streamers are pressed on the molten surface of sheet glass during the rolling process, and become permanently fused.

4. Fracture Glass

Fracture glass refers to a sheet of glass with a pattern of irregularly shaped, thin glass wafers affixed to its surface. Fracture glass is made from paper-thin blown shards or flakes of intensely colored glass fused to the bottom of sheets during the rolling process. Tiffany made use of such textured glass to represent, for example, foliage seen from a distance.

The irregular glass wafers, called fractures, are prepared from very hot, colored molten glass, gathered at the end of a blowpipe. A large bubble is forcefully blown until the walls of the bubble rapidly stretch, cool and harden. The resulting glass bubble has paper-thin walls and is immediately shattered into shards. These hand blown shards are pressed on the surface of the molten glass sheet during the rolling process, to which they become permanently fused.

5. Fracture-streamer Glass

Fracture-Streamer glass is fracture glass combined with hand-stretched streamers or strings of glass during the rolling process. Fracture-streamer glass refers to a sheet of glass with a pattern of glass strings, and irregularly shaped, thin glass wafers, affixed to its surface. Tiffany made use of such textured glass to represent, for example, twigs, branches and grass, and distant foliage.

The “fractures” are created by the addition of thin blown flakes of intensely colored glass, while the “streamers” are pulled or drawn strings of intense colors. Both fractures and streamers are quick-fused to the bottom of sheets during the rolling process.

Fracture and streamer glass is used primarily for backgrounds; the fractures suggest multitudinous leaves or flowers in the distance, while the streamers suggest twigs or stems. For this reason, fracture colors are usually selected to correspond to the colors used in leaf or flower foregrounds.

6. Ripple Glass

Ripple glass refers to a sheet of textured glass with marked surface waves. The texture is created during the glass sheet-forming process. A sheet is formed from molten glass with a roller that spins on it, while travelling forward. Normally the roller spins at the same speed as its own forward motion, and the resulting sheet has a smooth surface. In the manufacture of rippled glass, the roller spins faster than its own forward motion. The rippled effect is retained as the glass cools.

In order to cut ripple glass, the sheet may be scored on the smoother side with a carbide glass cutter, and broken at the score line with breaker-grozier pliers.

7. Ring Mottle Glass

Ring mottle glass is an opalescent glass in which rates of crystal growth have been controlled to create ring-shaped areas of opacity. The effect is a visual surface mottling. Ring mottle glass refers to sheet glass with a pronounced mottle created by localized, heat-treated opacification and crystal-growth dynamics. Tiffany's distinctive style exploited glass containing a variety of motifs such as those found in ring mottle glass, and he relied minimally on painted details.

This type of glass has a locally varying opacity; the “rings” are more opaque than the surrounding matrix. Ring mottled glass is used to provide color and image gradation that is non-streaky, or non-linear. The naturally rounded shape of each ring breaks up the more typical streakiness of stained glass. The artist, using ring mottles, can create shading and imagery unavailable from other glass types.

8. Drapery Glass

Glass sheets with multiple dramatic folds, likened to those in hanging drapes. Drapery glass refers to a sheet of heavily folded glass that suggests fabric folds. Tiffany made abundant use of drapery glass in ecclesiastical stained glass windows to add a 3-dimensional effect to flowing robes and angel wings, and to imitate the natural coarseness of magnolia petals.

To create drapery glass, the molten glass is shaped by taking a hand held roller and using it like a rolling pin to create "speed bumps" on the surface. It can also be tugged and pulled by hand using steel tongs to create the deep fabric-like folds in the surface. It is easy for the glassmakers to get burnt while making this unusual glass and extreme care must be taken while rolling the glass.

Dichroic glass

‘Dichroic glass’ is really a misnomer. The dichroic part is actually a very thin film of metal oxides which are too thin to stand alone and have therefore been layered onto a sheet of glass which acts as a substrate to lend the thin film strength. Dichroic glass is any glass that is coated with metallic oxides such as silicon, titanium and magnesium in a vacuum furnace using a technology called thin-film physics. Dichroic means 'two colors' and the glass is called this because it reflects one color but transmits another.

Dichroic glass is a high-tech spin-off of the space industry. "Dichroic" is defined as the property of having more than one colour, especially when viewed from different angles or from transmitted to reflected light. Hence dichroic glass is also referred to as "chameleon glass". For example, a particular formulation will appear blue, but shift the dichroic glass slightly and the color will transition to green.

Dichroic coated glass is produced by a process called "thin film physics" and is generally referred to as a colour separator. It's normally used as an interference filter in scientific measuring or correcting applications. It is transparent, has adequate rigidity, is stable, withstands relatively high temperatures, and is not affected by moisture, solvents or most acids.

Manufacturing Process

Dichroic Glass is made by applying a surface coating of one or more layers of transparent materials designed to create reflections of a specific wavelength in order to modify an optical effect. The coating itself is completely transparent. Dichroic glass can provide very crisp and vibrant colors.

The most commonly used coating materials are titanium oxides, zirconium oxides, silicon oxides and aluminum oxides. They are applied using a method called Vapour Deposition. The deposition occurs in a high vacuum chamber where the glass is suspended in the top of the chamber and rotated. The coating materials are placed in crucibles at the bottom of the chamber and bombarded with an electron beam that is focused and swept over the materials with electromagnetic fields. The heat generated by the bombardment vaporizes the materials, and the vapour condenses on the glass suspended above.

Dichroic coatings create some of the purest and most brilliant colours ever seen in glass. They are fragile and must be protected from abrasion unless they are reheated too close to the softening point. Once heated in this way, the coating becomes very durable. The resulting colour of the glass depends on the sequence of the many layers of coatings. Incredibly, the total thickness of the multi coatings is only between 3 to 5 millionths of an inch. It is a highly technical computerized manufacturing process.

The resulting Dichroic Glass is totally unlike normal coloured glass where light enters and part of the colour spectrum is absorbed, leaving the part not absorbed to be reflected. With Dichoric Glass all light entering is either transmitted or reflected (“dichromatic" means "two-colored"). These two sources have completely different colours, and importantly, the colours alter as the angle of view is changed. This results in fascinating and beautifully vibrant colours.

With the play of light together with its vibrant colour, Dichroic Glass is a prime tool used to add interest to any piece of work or project. With over 45 colours of dichroic doatings available that can be placed on “any” substrate (i.e glass), artists have unlimited freedom of expression.

Architectural Applications

There is an ever growing demand for the use of dichroic glass in architecture. Its resilience to weather and never-fading colors are prime material to enhance office buildings, custom homes, walkways, fountains, skylights, walls, lighting fixtures and more. Dichroic glass is also used in windows and curtain walls. Dichroic glass windows on the external wall maximize the entry of natural daylight.

In Other Industries

Dichroic Glass was originally created for the aerospace industry for satellite mirrors, but it now has many technical uses including lighting, fibre optics, infrared lasers, motion picture equipment, and more.

Crown Glass

Crown glass was one of the two most commonly used types of glass for windows up until the 19th century, the other being blown plate glass. The process of making crown glass was first perfected by French glassmakers in the 1320s. Crown glass is made without lead, chiefly by fusing fixed alkali with silica sand, to which is added some black oxide of manganese – which gives the glass a tinge of purple.

For the best crown glass, the ingredients must be prepared in the same manner as for mirrors, and mixed in the following proportions: 60 lbs. of white sand, 30 lbs. of pearlash, and 15 lbs. of nitre, 1 lb. of borax, and 1/2 lb. of arsenic.

Crown Glass Making Process

A blowpipe is dipped into melted glass, which is then blown into the form of a large globular bottle. A rod tipped with a blob of hot glass is so placed that the blob or "punty" sticks to the centre of the bottom of the blown globe. Spinning the semi-molten ball then causes it to flatten and increase in size, but only up to a certain diameter.

The globe is then detached from the blowpipe, heated, and rotated vigorously until it whirls out by centrifugal force into a flat disc or "table" having a blob or "bullion" of glass in the centre.

The finished “table” of glass was thin, lustrous, highly polished (by “fire-polish”), and had concentric ripple lines, the result of spinning; crown glass was slightly convex, and in the centre of the crown was the bull’s eye - a thickened part where the pontil was attached. This was often cut out as a defect, but later it came to be prized as evidence of antiquity. Nevertheless, and despite the availability of cheaper cylinder glass (cast and rolled glass had been invented in the 17th century), crown glass was particularly popular for its superior quality and clarity.

This process allows the colour range to be limitless; crown glass is used ecclesiastically, commercially, domestically and for restoration purposes.

Burmese glass

Burmese glass was patented in 1885 by the U.S. Mount Washington Glass Company. Queen Victoria was apparently awed by the beauty of this art glass and purchased a Burmese glass tea set. Thomas Webb and Sons, a British company, were then licensed to produce their own version of Burmese glass known as Queen's Burmeseware. Queen Victoria gave permission to name the art glass collection in her honour.

In addition to being adorned in dazzling colors, Burmese glass could be crafted into a shiny surface ware or one with a dull satin-like finish. The majority of Burmese glass however was given the duller acid-induced matte finish surface which ultimately became more popular with the public. Some Burmese glass designs displayed colorful enamels with artwork such as flowers, birds or fish. Burmese glass was blown, blow moulded, and press moulded.

Burmese glass can be produced in all sorts of shapes and forms, although it is most commonly used as ornamental vases or lamps, small fairy lights, candle shades, or as decorative tabletop items. It also comes unlined, which increases its attractiveness and value. Burmese glass has a fluorescent appearance.

Manufacturing Process

The process for producing Burmese glass begins with an ordinarily translucent white glass. Addition of uranium oxide gives a warm yellow color to Burmese glass, while the high degree heating or re-heating of the gold (a tincture of which is added) imparts the rosy pink shading. Intense heat directly influences the extent of shading. The combination of all three elements in varying degrees creates a breathtaking array of colors.

Burmese glass products also came with attached glass beads, making for a brilliant glowing effect. Another technique used to create Burmese glass was called coralene. In this process, the glassworker would fasten small beads to the surface of the glass with an enamel paste. When bright light passed through the beads and reflected off of the paste, the result would be a glowing effect in the overall art glass. There were occasional instances where they would also apply gilded decorations, but for the most part, the appeal and attraction of Burmese glass lay in its elegant simplicity.

Annealed Glass

Annealed glass is glass produced without internal stresses imparted by heat treatment, i.e., rapid cooling, or by toughening or heat strengthening. Glass becomes annealed if it is heated above a transition point then allowed to cool slowly, without being quenched. Glass is treated with heat in order to change its properties by the annealing process. Annealed glass is the most common glass used in windows. Annealed glass is also known as a standard sheet of float glass.

Annealing is actually a process of slowly cooling glass to relieve internal stresses after it is formed. The glass, formerly annealed on shelves in a melting furnace, is now usually carried on rollers through temperature-controlled kiln known as a Lehr (annealing ovens). The shaped glass is annealed to relieve stresses caused by manipulation, then is slowly cooled.

Glass which has not been annealed is liable to crack or shatter when subjected to a relatively small temperature change or mechanical shock. Annealing glass is critical to its durability. If glass is not annealed, it will retain many of the thermal stresses caused by quenching and significantly decrease the overall strength of the glass.

Annealing Process



The glass is heated until the temperature reaches a stress-relief point, that is, the annealing temperature (also called annealing point) at a viscosity, η, of 1013 Poise = 1012 Pa•s, at which the glass is still too hard to deform, but soft enough for the stresses to relax. The piece is then allowed to heat-soak until its temperature is even throughout.

Soaking is a process of subjecting glass to a steady temperature. The higher the temperature the glass is soaked at, the shorter the period the glass needs to be exposed to such a temperature. Of course, glass exposed to very high temperatures requires longer time to cool down.
Caution should be taken to not expose the glass to a temperature that can adversely affect its structure. On the contrary, when glass is annealed at lower temperatures, it takes longer soaking time but requires commensurately less cooling time. The type of soak a glass should be subjected to depends on the type of glass.

The time necessary for soaking varies depending on the type of glass and its maximum thickness. The glass is then slowly cooled at a predetermined rate until its temperature is below the strain point (η = 1014.5 Poise). Following this, the temperature can safely be dropped to room temperature at a rate limited by the heat capacity, thickness, thermal conductivity, and thermal expansion coefficient of the glass. After the annealing process the material can be cut to size, drilled or polished.

At the annealing point (η = 1013 Poise) stresses relax within several minutes, while at the strain point (η = 1014.5 Poise) stresses relax within several hours.[2] Stresses that are still present below the strain point are permanent.

Float glass is annealed during the process of manufacture. However, most toughened glass is made from float glass that has been specially heat-treated. Annealed glass breaks into large, jagged shards that can cause serious injury, thus considered a hazard in architectural applications.

Care should be taken when choosing locations to install annealed glass. Building codes in many parts of the world restrict the use of annealed glass in areas where there is a high risk of breakage and injury, for example in bathrooms, indoor panels, fire exits and at low heights in schools or domestic houses.

Annealed glass has the surface strength that provides the wind-load performance and thermal-stress resistance needed in most architectural applications. In areas of high wind loads, or in conditions where higher-than-normal thermal stresses occur, heat-treated glass may be required.

Curved Annealed Glass

Curved annealed glass is used in applications that do not require the use of safety glass. This includes shop windows and display counters. Curved annealed glass can be produced for custom designs and has the advantage of being able to be cut and processed after it has been bent to its desired shape/form.

Russia Nightclub Fire: Fire Safety Lapse Claims over a Hundred Lives

The News

Russia is still coming to terms with its most deadly fire since Soviet times after 109 people died and more than 130 were injured in a blaze at a packed provincial nightclub on December 4, 2009. The fire started when a performance artist threw pyrotechniques too high and burnt the ceiling which quickly ignited the walls. The Lame Horse club, where the disaster occurred, was celebrating its eighth anniversary on the day.

One of the fireworks, tossed into the air and intended to be caught, hit the plastic covering of the ceiling, igniting the explosive. The decorative woven twigs affixed to the walls and ceiling also caught fire, filling the building with smoke. Panic gave way to a stampede when many patrons found themselves cut off from one public exit, management having sealed off other doors and the public unaware of emergency exits behind the stage.

Fire Safety: Why & How

Clearly, the Lame Horse Club owners had been callous about this aspect of safety, given that Russia’s Emergency Situations Minister Sergei Shoigu stated that the owners had been fined twice in the past for breaking fire safety regulations.

However, “Fire Safety” is not just a fancy term, and the implementation process not as complicated as is made out to be; there are some key elements of the process which can be easily adhered to.

• Building a facility in accordance with the version of the local building code

• Maintaining a facility and conducting oneself in accordance with the provisions of the fire code. This is based on the occupants and operators of the building being aware of the applicable regulations and advice.

Examples of these include:

• Not exceeding the maximum occupancy within any part of the building.

• Maintaining proper fire exits and proper exit signage (e.g., exit signs pointing to them that can function in a power failure)

• Placing and maintaining fire extinguishers in easily accessible places.

• Properly storing/using, hazardous materials that may be needed inside the building for storage or operational requirements (such as solvents in spray booths).

• Prohibiting flammable materials in certain areas of the facility.

• Periodically inspecting buildings for violations, issuing orders to comply and, potentially, prosecuting or closing buildings that are not in compliance, until the deficiencies are corrected or condemning it in extreme cases.

• Maintaining fire alarm systems for detection and warning of fire.

• Obtaining and maintaining a complete inventory of firestops.

• Ensuring that spray fireproofing remains undamaged.

• Maintaining a high level of training and awareness of occupants and users of the building to avoid obvious mistakes, such as the propping open of fire doors.

• Conducting fire drills at regular intervals throughout the year.

Practical Application



An example of how following these rules could have proved a life-saver in the Lame Horse lies in the fact that most victims died from smoke inhalation and carbon monoxide poisoning. There are fireproofing devices available that cut off not just the fire itself but even the radiant heat that emanates from it, as also the smoke and gases that are just as deadly. And in a place like a nightclub where the aesthetics imparted by tasteful and expensive interior décor is just as important as safety, fire resistant glass which offers this kind of protection is now abundantly available. Fire doors that are thoroughly tested for fire resistance and also adorn building interiors with their seemingly delicate appearance are one of the best choices for this purpose.

Also, it is important that a fire exit door opens towards the outside (persons trapped inside must be able to open the door by pushing and not pulling it). In the past, there have been cases where victims have died not because of the fire itself but thanks to a stampede caused by large numbers of people rushing towards the fire exit door at the same time, making it impossible for the door to be pulled open.

NOT an option

Russia records up to 18,000 fire deaths a year, several times the per-capita rate in the United States and other western countries; worldwide, nightclub fires have killed thousands of people. Another similar accident anywhere in the world will only establish deliberate carelessness by responsible authorities, because as is abundantly clear, fire safety is neither complicated nor expensive; not as compared to a human life anyway.

Fire Safety: Is Your Glass Fire Resistant? Another Wake-up Call

Yet another fire accident, still a lot left to chance rather than appropriate safety measures. The fire that broke out on Tuesday morning in the cafeteria of the Cognizant Technology Solutions (CTS) office at Kolkata once again drove home this point. An apparent gas leak is said to have started the fire, injuring two cooks and causing considerable damage to assets.

Police said gas that leaked from a cylinder caused the fire at around 9.40 am when one of the cooks, Chandrasekhar, was apparently pushing the cylinder below the kitchen table. Both burners of the oven had already been lit. With the regulator removed and gas leaking freely, the flames spread from the burners in a flash, injuring Chandrasekhar.

The obvious learning is that gas cylinders must never be handled carelessly. A suspended regulator is a recipe for disaster. Apart from this, measures to control and restrict fire in case it breaks out must also be taken.

Extinguishing is usually the reactive action that is deployed in case of a fire accident. But insulation could be the smarter thing to do. Different kinds of fire-resistant substances are abundantly available, but if aesthetics, visibility as well as fire security are to be taken care of, then fire-proof glass would be the ideal solution. With functionalities such as cutting out the fire itself, smoke, gases and even radiant heat, fire resistant glass has almost no equivalent substitute.

The usage of the right type of glass could be a life-saver too. For instance, fortunately wired glass (glass laced with very sharp and fine strands of steel) had not been used to glaze the kitchen exteriors. Had that been the case, rescue teams would have found it extremely difficult to enter the premises.

Be it the use of a fire-resistant glass or some other fire-retardation substance, the point is that fire safety is not an option and that we need to wake up to it, and soon.