Types of glass

Below is a list of each type of glass with their relevant descriptions.


 WindowWIndowType of window

Annealed or float glass This is basic, flat glass renowned for its optical clarity. Annealed glass is the product directly after the float process. It can be further processed into more advanced products, such as laminated glass or toughened glass. However, if left as is, it can be used in some end products, such as double-glazed windows. It is available in clear; toned; high-performance toned; ultra-clear, low-iron; and low-e, pyrolitic-coated forms.
Insulating glass or double glazing Most glass types can be used to create an insulating glass unit. They are formed by bonding two or more panels of glass to either a metal or thermoplastic spacer. Then, the space between the panes is filled with either air or argon gas.
Toughened glass Toughened glass is more resistant to breaking than annealed glass, and it breaks into small square fragments, providing a safety advantage. It is made by heating a sheet of annealed glass to above 600 °C, and then rapidly cooling the surfaces while the inner glass stays hot. The different cooling rates result in compressive stresses on the surface, balanced by tensile stresses in the body of the glass. Toughened glass is used for both buildings, such as in sliding doors, and automobiles, such as for windshields.
Laminated glass This is made from two or more layers of glass with a polymeric material bonded between the layers. It is either produced by using heat to sandwich Poly Vinyl Butyral between the glass layers, or a resin is poured into this space. Laminated glass offers a safety advantage because the interlayer holds the glass together on impact, preventing shattering. Laminated glass can have added colour, sound-dampening, fire resistance and ultraviolet filtering. This type of glass is used in the building and automotive industries to make building façades and car windscreens, for example.
Coated glass Surface coatings are applied to glass to modify its appearance; to give it special reflection, transmission or absorption properties; to make it scratch or corrosion resistant; or for ease of maintenance. Coatings can be applied by exposing the glass, still in the float line, to vapours which bind to the glass’s surfaces, or vapours can be applied to cold glass in a vacuum. Coated glasses can be toughened, laminated or used to make an insulating glass unit.
Security glass This glass is laminated using multiple layers and rigid interlayers in order to resist physical or ballistic attacks and bomb blasts.
Screen printed glass This glass is created by screen printing and fusing ceramic paint to toughened glass.
Mirrored glass Mirrored glass is made by applying a silver, aluminium, gold or chrome metal coating to one side of a sheet of glass, and then sealing it with a protective layer. Some mirrored glass includes a vinyl backing too, for safety. To create one-way mirrors, a thinner metal coating is used with no additional sealing.
Patterned glass Glass becomes patterned when it is passed between rollers, with the negative pattern on their surface, straight after the glass exits the furnace where it is made. Patterned glass is used as decoration, or when light but not transparency is desired.
Self-cleaning glass This glass, used for exteriors, has a pyrolitic coating that dissolves dirt and sheds water.


Compiled by Daniella Favis for Builders' Space. Source: SAGGA.

For more information on the uses of these types of glass, see The uses of glass.