This week’s video comes courtesy of PPG. It demonstrates modern techniques of making large sheets of flat glass that has a smooth surface – something that perplexed glass-makers for centuries.

The first advances in automating glass manufacturing were patented in 1848 by Henry Bessemer, (of steel-making fame), who developed a steelmill-like, but very expensive process to produce a continuous ribbon of flat glass force under heat between rollers. Another old method formed large sheets of plate glass by casting a large puddle on an iron surface. Both of these processes required secondary polishing.

Then in the 1950s, Sir Alastair Pilkington and Kenneth Bickerstaff created the first successful commercial application for forming a continuous ribbon of glass using a molten tin bath on which the molten glass flows unhindered under the influence of gravity. Full scale profitable sales of float glass were first achieved in 1960.