Float glass is formed by “floating” a ribbon of molten glass over a pool of molten tin. Float glass manufacturing is a highly-automated 24-hour operation, capable of producing up to 800 tons of glass per day.

Float glass features uniform thickness and very smooth, glossy, “fire-polished” surfaces – a result of the exposure to intense heat during the manufacturing process. It is nearly colorless with a slight greenish-blue cast, observable through its edge. The visible light transmittance of float glass typically ranges from 75% to 92%, depending on the glass thickness and whether it is regular or low-iron (optically clear) glass.

The quality standards for float glass are defined by ASTM C 1036 – Standard Specification for Flat Glass.