Smart Glass

In recent years, the market for light-controlSmart Glass has expanded due to the increasing demands for energy efficiency and heat and light control, automated shading, privacy, and design and engineering innovation.

Smart Glass or Switchable Glass is a product of cutting-edge technology that allows users to block either all light or just some by simply turning a knob or pressing a button. This type of light control could potentially save tremendously on heating, cooling and lighting costs.

Smart Glass technology basically means controlling the transmission of light through glass by using electrical power. By applying a variable voltage to the glass, the amount of transmitted light can be controlled. Switching speed and the consistency of a tint change are among the most important attributes to potential users of smart glass technology.

The processing technique of Smart Glass is to combine Smart Film with glass through a certain process to ensure reliable use.

Why it is so called?

When a product is called “smart”, it simply means it is programmed with an auto-intelligence capable of operating a single task. And the same goes for smart glass: instead of relying on glass treatments to block the light, these specially designed, energy-efficient glass panes automatically control the sun's solar penetration.

How does Smart Glass Work?

Switchable glass panes dim and brighten at will. When you want sun to shine through your windows, simply flip a switch to turn off the tint. You want to open a room, another flip and the windows will blur, become opaque, or slowly darken. Though they all perform the same task, there are several types of smart glass available. One of the original forms is photo chromatic technology which doesn't require manual operation. Similar to sunglasses, these panes immediately tint when the sun hits, which is efficient since they don't call for any electricity or hands-on direction.

Smart glass technologies include electrochromic devices, suspended particle devices and liquid crystal devices

1. Suspended Particle Devices

Suspended Particle Devices are constructed with two panes of glass separated by a conductive film with suspended, light absorbing, microscopic particles. These microscopic particles within the Suspended Particle Devices (SPD) absorb light, thus preventing it from passing through the film. When the electrical current is added to the film, the particles align themselves to allow light through the glass. The switchable system consists of a non-toxic film between two panes of glass - the higher the current, the more arranged the particles are, and consequently more light is allowed through the glass or plastic.

When the current is switched off, the particles are scattered, inhibiting light penetration. SPD films, which operate off an AC voltage or battery power, consume a very minute power of 0.05 watts/square feet maximum. Users can instantly and precisely control the transparency of the window by manually adjusting a dial connected to a rheostat or automatically setting the opaqueness by programming a photocell.

Smart glass using SPD technology takes several seconds to change from dark to clear, and tint changes are consistent regardless of panel size.

2. Liquid Crystals

Working similarly to SPD technology, these products are black and white: turn it on, they line up to permit light; turn it off, you're in the dark again. Liquid crystal smart glass changes its properties the most quickly of all—from translucent to transparent in milliseconds—and tint changes occur consistently regardless of panel size. Liquid crystal smart glass does not offer a shading benefit, but the view through the glass is blocked when in its translucent state. As such, this product is primarily used for interior needs (e.g., bathrooms) where privacy is required.

3. Electrochromic Glass

Electrochromic Glasses work in the opposite manner. When a current is supplied, they darken and when electricity is withheld they become clear. Another unique aspect of these is that they aren't so black and white. Instead they are able to create varying levels of light penetration, allowing total management of the sun's power. Sometimes it takes several minutes to change shades and typically electrochromic glass works from the outside to the center, but it also doesn't require a constant stream of electricity. Once the initial tint is achieved, no more power is needed.

The switching speed of electrochromic glass is slowest overall and varies depending upon the size of the panel (larger panels typically take many minutes to switch). The consistency of tint changes also varies, with larger panels sometimes exhibiting tint changes that begin at the glazing’s outer edges and then move inward (known as the “iris effect”).

Applications

Smart glass can be applicable in the following areas:

• Several professions and industries such as the house, the fitment and the automobile.
• In the industry of real estate/decoration, it can be applied in high-stand apartments, villas, town houses, office building and stores.
• Building walls, doors, windows and indoor separation, decorations.
• The big area of the projection wall.
• The controllable options of offices (meeting rooms, supervision rooms)
• The controllable options of public facilities (restaurants, hotels, banks, hospitals, the recreational places)
  

Applications of smart glass include building windows, doors and skylights; automobile, boat and aircraft windows; appliance windows, computer screens and cell phone screens. Its use in home and residential windows can all but eliminate the need for blinds or shades, and it fits in with the "green movement" by helping with interior heating and cooling.

Advantages

• Smart glass does not need cleaning and does not fade in the sun like cloth and plastic.
• It only requires a small amount of energy to sustain (powering several windows at once uses less electricity than a single light bulb) and electrochromic glass hardly needs any electricity at all.
• Can assist the air condition to economize energy and can obstruct ultraviolet radiation.
• Allows enough light even when opaque, tenders bright indoors.

Dynamic glazing technologies

Smart glass represents a category of glazing materials that visibly change their properties in response to a stimulus. In doing so, smart glazing in windows, doors, skylights and partitions offer varying levels of dynamic control of light, glare and heat.

1. Passive smart glass

Passive smart glass operates with no electrical interface and is typically found in small-format applications. Self-dimming eyewear that reacts to the presence of ultraviolet light is an example.

2. Active smart glass

The most exciting development in the architectural arena is active smart glass products, including those using liquid crystal, suspended particle device or electrochromic technology. Active smart glass requires an electrical stimulus to change its light-control properties, and power consumption levels are very low. The operating performance of active smart glass depends on the type being considered.

High-performing smart glass products provide unprecedented levels of advanced light-control while also making instant and dramatic design statements. Sleek and innovative, smart glass is tremendously empowering. Just as significant is its array of functional benefits (tunable shading, privacy, glare reduction and remarkable energy efficiency) that support the sustainable design goals of resource conservation and the well-being of building occupants.

Frosted glass

Frosted glass is a glass which has been rendered opaque through a process which roughens or obscures the clear surface of the glass. Frosted glass can enhance the beauty of windows, glass doors, or glass cabinets. This technique adds warmth and style to any décor.

Frosted glass or opaque glass is produced by the sandblasting or acid etching of clear sheet glass. It has the effect of rendering the glass translucent by scattering of light during transmission, thus blurring visibility while still transmitting light.

The frosted glass effect can also be achieved by the application of vinyl film, used as a sort of stencil on the glass surface. "Photo-resist” or photo-resistant film is also available, which can be produced to mask off the area surrounding a decorative design, or logo on the glass surface. A similar effect may also be accomplished with the use of canned frosted glass sprays.

Glass frosting can be accomplished on glass of any colour, and can look quite striking and distinctive. Care should be taken while working with acid to produce frosted glass. Eye and face protection should be worn when making frosted glass.

Various Frostings

A frosted appearance may be given to glass by covering it with a mixture of magnesium sulphate. When this solution dries, the magnesium sulphate crystallizes into fine needles. Another formula directs a strong solution of sodium or magnesium sulphate, applied warm, and afterwards coated with a thin solution of acacia.

A more permanent "frost" may be put on the glass by painting with white lead and oil, either smooth or in stipple effect. The use of lead acetate with oil gives a more pleasing effect, perhaps, than the plain white lead. If still greater permanency is desired, the glass may be ground by rubbing with some gritty substance.

For a temporary frosting, dip a piece of flat marble into glass cutter's sharp sand, moistened with water; rub over the glass, dipping frequently in sand and water.

If the frosting is required very fine, finish off with emery and water. Mix together a strong, hot solution of Epsom salt and a clear solution of gum arabic; apply warm. Or use a strong solution of sodium sulphate, warm, and when cool, wash with gum water. Or daub the glass with a lump of glazier's putty, carefully and uniformly, until the surface is equally covered. This is an excellent imitation of ground glass, and is not disturbed by rain or damp. The production of imitation frosting entails little expense and is of special advantage when a temporary use of the glass is desired.

Manufacturing Process

The frosted glass production requires a thorough cleaning of the glass surface before beginning the frosted glass process.

Frosted glass frosting formula is mixed with wallpaper paste, white powder paint pigment, water, and acid free PVA glue. All ingredients are mixed well, except the glue until having a pudding texture for the frosted glass project. Once this texture is achieved, a drop of glue is added so that the mixture will adhere to the glass.

The stencil should be placed on the glass, using painter's tape to secure it to the glass surface. The frosted glass mixture is applied using a stiff brush over the stencil. This is continued until all of the areas of the glass that we want to turn into frosted glass have been coated.

Applications

• To obtain visual privacy while admitting light.
• Decorative patterns may be imposed upon otherwise plain glass by using wax or other resist to retain transparent areas.
  

A sheet of frosted glass is an excellent privacy aid because it admits light without allowing people to see through it. In medical offices and bathrooms, the use of a curtain or blinds would make a room gloomy and unpleasant to be in. Frosted glass, on the other hand, keeps a room bright and friendly while still allowing people to be comfortable. People may also use frosted glass for privacy in entryways in urban areas.

Commercially produced frosted glass is usually frosted with acid etching or sandblasting. Acid etching is used to make frosted glass with a pattern. Patterned glass sometimes appears in ornamental windows, as well as in glasses, mirrors, vases, and other glassware around the house. The pattern can be simple or extensive, and it may include floral or geometric elements. Sandblasting is used to frost an entire sheet of glass, for installation in places like bathrooms and other areas where people might want privacy.

Patterned glass

Patterned glass is a kind of decorative translucent glass with embossed patterns on one or both surfaces. Pattern Glass or Decorative Glass or Rolled Glass is generally used where privacy or obscurity is desired but light transmission is still important. With the special property of decoration, patterned glass can allow light to pass through, at the same time, it can also prevent clear view. Usually it transmits only slightly less light than clear glass.

Patterned glass is not-perfectly-smooth structure with different patterns impressed on it. The depth, size and shape of the patterns largely determine the magnitude and direction of reflection.

Basically patterned glass has a pattern impressed on one side of the glass which prevents someone from seeing though it, for privacy. Pattern glass can also be ordered in various tints as well. A common application of this sort is when used in privacy walls to separate one room from another.

Rolled Pattern glasses are available in a wide variety of patterns, to add the perfect complement to many interior designs. Heavy patterned glasses provide added strength and support, and are a fast-growing product category. According to customers' requirements, patterned glass can be cut, ground, drilled, tempered, laminated, etc.

Production

Patterned glass is made with a rolled glass process. All rolled patterned glass begins as a batch of materials, including silica sand, soda, and lime. These materials are melted together in a tank, and then the molten glass mixture is fed onto a machine slab. The glass flows under a refractory gate which controls glass volume and speed then moves between two counter-rotating, water-cooled rollers. One of these rollers is embossed, imprinting a distinct pattern onto the soft surface of the glass while the other roller is smooth.

The result is a piece of glass that is patterned and textured on one side, while smooth on the reverse. The distance between the two rollers determines the ultimate thickness of the glass. After it moves between the rollers, patterned glass is annealed or cooled slowly in order to remove any residual stresses. Rolled patterned glass can then be cut into standard sizes or cut into customized sizes for a specific customer application. The glass is then inventoried and ready for delivery.

Applications

Rolled glasses are used in commercial, residential, and specialty applications. End uses include shower doors and tub enclosures including frameless shower doors interior partitions, translucent door and window treatments, foyers and vestibules, patio furniture, shelving, decorative furniture, and lighting fixtures. Comprehensive range of soft natural colours compliments and harmonizes with modern building materials to provide an exciting and different look to new and existing buildings. Pattern glasses are available in large amount of patterns. Patterned glass is most often found in bathroom windows.

Patterned glass is applied to all kinds of public and private places, such as office, meeting room, hotel, hospital, bath room, washroom, etc. It is also widely used as glass table, glass shaft and lampshade and so on. Mainly used in interior partitions, interior design, decorations, street furniture etc.

Chemically strengthened glass

Chemically strengthened glass is a type of glass that has increased strength as a result of a post-production chemical process. Chemical strengthening is the name given to glass products that have been strengthened by means of an ion-exchange process. It is a surface treatment which occurs at a temperature lower than glass melting temperature. The process is particularly useful for thin glass, tiny glass and shape glass which cannot be tempered by ordinary physical tempering.

Chemically strengthened glass is typically six to eight times the strength of float glass. In the case of breakage, chemically strengthened glass breaks into bigger pieces which are not as sharp as those of non-toughened glass. The surface compression condition which is higher in the case of a chemically strengthened glass also involves an increase of flexion resistance, which is one of the main characteristics of chemically strengthened glass.

Chemical strengthening results in a strengthening similar to toughened glass. Chemically strengthened glass has little or no bow or warp, optical distortion or strain pattern. This differs from toughened glass, in which slender pieces can be significantly bowed.

Chemically strengthened glass may be cut after strengthening, but loses its added strength within the region of approximately 20 mm of the cut. Similarly, when the surface of chemically strengthened glass is deeply scratched, this area loses its additional strength. Chemically strengthened glass retains its colour and light transmission properties after treatment.

Chemically strengthened glass offers an improved scratching, impact and bending strength, as well as an increased temperature stability.

Manufacturing process

The glass is chemically strengthened by a surface finishing process. The glass to be treated is dipped into a bath of dissolved potassium salts at a temperature about 380oC for duration from 4 to 30 hours, producing an ionic exchange between the superficial sodium ions in the glass and potassium ions inside the bath. The cycle time would be greatly reduced if the glass is made of certain elements such as lithium or magnesium because ion mobility between potassium and these elements is a lot faster. The process parameters such as ion exchanging time and temperature would be modified according to the type of glass to be treated and the required strengthen specification.

The introduction of potassium ions which are larger in size than the sodium ions results in the establishment of a system of residual stress characterized by compression stretches on the surface counterbalanced by traction stretches within the glass

Sodium ions and thus, creates stress on glass surface. During cooling, the potassium on surface shrinks little while the sodium in inner shrinks larger. Hence, stress is induced between glass surface and inside and consequently, the glass is strengthened.

Advanced process

There also exists a more advanced two-stage process for making chemically strengthened glass, in which the glass article is first immersed in a sodium nitrate bath at 450 °C, which enriches the surface with sodium ions. This leaves more sodium ions on the glass for the immersion in potassium nitrate to replace with potassium ions. In this way, the use of a sodium nitrate bath increases the potential for surface compression in the finished article.

Classifications

Chemical strengthened glass is classified by two strength components: surface compression and depth of layer (DOL). Surface compression values relate to flexural (bending) strength (MOR), impact strength, hardness penetration (scratching) and thermal shock resistance. Depth of layer values relate primarily to the amount of sustained abrasion resistance and the impact resistance of the surface compression layer.

Applications

Chemically strengthened glass was used for the aircraft canopy of some fighter aircraft. The chemically treated glass boasts a transparency range from the UV through the visible and into the infrared. This permits weapons systems designers to operate guidance devices whether they are CCD, radio frequency, infrared or laser based. The material's proponents stress that chemically treated glass is not just for use in military applications.

It can be used in numerous applications that demand toughness and optical clarity. The material is also useful for viewports, protective covers, and front surface optics in hostile environments whose elements may include high temperature, high pressure and vacuum conditions. Less demanding applications include point of sale scanner windows used in grocery store and retail scanners.

Wired Glass

Wired glass is a type of glass into which a wire mesh is embedded during production. Wired glass has an impact resistance similar to that of normal glass, but in case of breakage, the mesh retains the pieces of glass. This product is traditionally accepted as a low-cost fire-resistant glass. Wired glass can be tinted by aerosol or electricity. Common colours are golden-yellow, green, light blue and violet-rose.

Wired glass is manufactured primarily as a fire retardant, with wire mesh inlaid in the glass to prevent it from shattering and breaking out under stress or when exposed to high temperatures. With the window intact, the glass keeps the fire at bay, protecting those on the other side from the harmful effects of smoke and flame.

However, in recent times, experts warn against the use of wired glass as a fire-resistant substance. This because although the mesh may prevent the fire from penetrating, by itself it could prove dangerous, being made of fine, sharp wires which can hurt. Today, special fire-resistant glass is available, which is devoid of the wire mesh as a component and can cut off not just the fire but even smoke, gases and deadly radiant heat.

Wired glass is made as a part of the rolled glass manufacturing process. Rolled glass is manufactured by passing molten glass from a furnace through a series of rollers to obtain the desired thickness and pattern. The rolled glass process is used to create wired glass, figured or patterned glass, and art/opalescent/cathedral glass.

Wired glass is produced by continuously feeding wire mesh from a roller into the molten glass ribbon just before it undergoes cooling. A steel wire mesh is sandwiched between two separate ribbons of semi-molten glass, and then passed through a pair of metal rollers which squeeze the "sandwich of glass and wire" together. Wired glass may be further processed by grinding and polishing both surfaces, producing "polished wired glass”.

Fused Glass

Fusing glass in a kiln is a fascinating technique that enables artists to create unique and breathtaking designs in glass. Fused glass is also referred to as kiln-formed glass, art glass fusion and warm glass. The “warm” of warm glass is between 1,100 and 1,700 degrees Fahrenheit (600 and 925 degrees Celsius). At these temperatures, glass softens enough that when pieces of glass are heated and pressed together, they will fuse into a single seamless piece. This is the underlying principle behind glass fusing.

Glass Fusing

Glass fusing is the process of using a kiln to join together pieces of glass. If you apply heat to glass, it will soften. If you continue to apply heat, the glass will become more fluid and flow together. Two or more pieces of glass will stick to each other. When the right kind of glass is heated and then cooled properly, the resulting fused glass piece will be solid and unbroken.

Fused glass is normally fired (heat-processed) in a kiln at a range of high temperatures from 593 °C (1,099 °F) to 816 °C (1,501 °F). There are 3 main distinctions for temperature application and the resulting effect on the glass. They are as follows:

1. Slumping

2. Tack fusing

3. Full fusing

1. Slumping

Firing in the lower ranges of these temperatures 593–677 °C (1,099–1,251 °F) is called slumping. Slumping is a categorical description of an area of techniques for the formation of glass by applying heat to the point where the glass becomes plastic. The increasing fluidity of the glass with temperature causes the glass to 'slump' into the mould under the force of gravity. Glass is most commonly heated in an oven, often using glass in a sheet form and “slumping” it over a form or into a mould.

Moulds are generally made of high temperature plaster, clay coated with plaster or another release agent, graphite, sand mixed with a bonding agent, steel, or other materials. At the point where the glass has achieved the desired form the heat is quickly vented and the temperature reduced to prevent further movement of the glass and then it is stabilized at its respective annealing temperature and annealed.

2. Tack Fusing

Tack Fusing Glass refers to the effect that is obtained when two or more pieces of glass are heated to approximately 1350 to 1375 degrees F. This temperature range will result in any pieces of glass that are in contact with each other fusing together, while still allowing each piece to retain its' original shape, size and thickness.

3. Full Fusing

Several pieces of glass fused into a single finished piece of uniform thickness by heating them to somewhere between 1450 and 1475 degrees F is known as Full fusing. At these temperatures your glass will have melted enough to combine and flow together into a single piece of fused glass. This piece may be a finished piece or a starting point from which you cold work, cut or reshape the piece prior to another fusing.

Techniques

Most contemporary fusing methods involve stacking, or layering thin sheets of glass, often using different colors to create patterns or simple images. The stack is then placed inside the kiln (which is almost always electric, but can be heated by gas or wood) and then heated through a series of ramps (rapid heating cycles) and soaks (holding the temperature at a specific point) until the separate pieces begin to bond together. The longer the kiln is held at the maximum temperature the more thoroughly the stack will fuse, eventually softening and rounding the edges of the original shape.

Once the desired effect has been achieved at the maximum desired temperature, the kiln temperature will be brought down quickly through the temperature range of 815 °C (1,499 °F) to 573 °C (1,063 °F) in order to avoid devitrification. It is then allowed to cool slowly over a specified time, soaking at specified temperature ranges which are essential to the annealing process. This prevents uneven cooling and breakage and produces a strong finished product. This cooling takes place normally for a period of 10–12 hours in 3 stages.

The first stage- the rapid cool period is meant to place the glass into the upper end of the annealing range 516 °C (961 °F). The second stage- the anneal soak at 516 °C (961 °F) is meant to equalize the temperature at the core and the surface of the glass at 516 °C (961 °F) relieving the stress between those areas. The last stage, once all areas have had time to reach a consistent temperature, is the final journey to room temperature. The kiln is slowly brought down over the course of 2 hours to 371 °C (700 °F), soaked for 2 hours at 371 °C (700 °F), down again to 260 °C (500 °F) which ends the firing schedule. The glass will remain in the unopened kiln until the pyrometer reads room temperature.

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.