Float glass is manufactured using a melt process whereby recycled glass, silica sand, lime, potash and soda are melted in a furnace and floated onto a bed of molten tin. The molten mass solidifies slowly while flowing over the bed of molten tin, after which it is annealed to remove stresses induced during the cooling process. Annealing also allows the glass to reach a more stable state resulting in a higher density and higher refractive index.
Tinted float glasses are made by adding colouring agents during the melt process. Common colours include grey, green, bronze and blue. While tinting may provide aesthetic alternatives to clear glass, tinted glasses also provide materials with different properties including heat and light transmission (and/or reflectance), ultraviolet transmission and insulation properties.
Reflective glasses are also available for applications where light transmittance is an important design factor. These glasses have a metallic coating applied during manufacture
Typical thicknesses range from 2mm to 19mm for commercial applications.