Windows have come a long way over the years, and a large part of that is due to the evolution of glass production over time. During Roman times, broadsheet glass was the first type of glass to ever be manufactured in Britain, and it involved having an elongated balloon of glass blown. After the blowing process had been completed, the ends were carefully cut off and the cylindrical section was then split and flattened on an iron plate. Unfortunately, this glass was of an extremely poor quality and its small size meant that it wasn’t practical to use for much else other than leaded lights. As techniques improved, other types of glass began to be produced and used in windows in earnest: