This article looks more specifically at how we make the types of glass, specifically how we heat and cool it. The variance in how we manufacture glass gives the different types their distinct properties. Some glass is stronger or more energy efficient than other types, for example.

This glossary is a good place to start.

 

• Float glass. Float glass is a flat, even type of glass; it’s the basic type of glass in most modern windows.
• Annealed glass. Annealed glass is float glass that has been slowly cooled; it’s ordinary window glass, before it is coated or treated for strength or energy efficiency.
• Heat strengthened glass. This type of glass refers to annealed glass that has been reheated and cooled rapidly. Heat-strengthened glass is twice as strong as annealed glass.
• Tempered glass. Tempered glass, or safety glass, is float glass that has been heated to about 1200 degrees Fahrenheit and then rapidly cooled. It breaks into small, dull pieces.
• Heat soak tempered glass. Heat soak tempered glass is specially heated to create extra strong safety glass.
• Laminated glass. Laminated glass is a type of safety glass that does not easily break, and when it does, it typically stays in the frame.
• Insulated glass. Insulated glass is made from two or more pieces of glass with an air-filled space in between.
• Gas filled glass. Gas filled glass has a layer of gas (either argon or krypton) between the panes of glass; this gas helps insulate the windows.