Cylinder glass
Historic England 2020 Stained Glass Windows: Managing Environmental Deterioration, Swindon, Historic England, published in 2020 defines broad glass, or cylinder glass as: “The principal method of making sheet glass by hand, developed in the early Middle Ages, and still in use. The glass maker swings a bubble of molten glass back and forth whilst blowing, producing an elongated balloon. The end of the balloon is opened out using a hot iron tool, and it is then cut from the blowing rod to produce a cylinder of glass. This is scored down its length and returned to a kiln, where the heat causes the cylinder to open out along the scored line and flatten into a sheet.”
Maintaining traditional plain glass and glazing, published on 1 November 2007 by Historic Scotland, states: ‘Cylinder glass (also known as ‘broad, ‘sheet’, or ‘muff’ glass) was made by blowing a cylinder of molten glass. This cylinder was cut along its side and flattened out in a furnace, giving the glass a slightly rippled surface. It can also be recognised by the pattern of the ‘seed’ which consists of elongated air bubbles that lie in straight parallel lines within the glass. Popular until the first half of the 18th Century.’
[edit] Related articles on Designing Buildings
Featured articles and news
ECA, JIB and JTL back Fabian Society call to invest in skills for a stronger built environment workforce.
Women's Contributions to the Built Environment.
Calls for the delayed Circular Economy Strategy
Over 50 leading businesses, trade associations and professional bodies, including CIAT, and UKGBC sign open letter.
The future workforce: culture change and skill
Under the spotlight at UK Construction Week London.
A landmark moment for postmodern heritage.
A safe energy transition – ECA launches a new Charter
Practical policy actions to speed up low carbon adoption while maintaining installation safety and competency.
Frank Duffy: Researcher and Practitioner
Reflections on achievements and relevance to the wider research and practice communities.
The 2026 Compliance Landscape: Fire doors
Why 'Business as Usual' is a Liability.
Cutting construction carbon footprint by caring for soil
Is construction neglecting one of the planet’s most powerful carbon stores and one of our greatest natural climate allies.
ARCHITECTURE: How's it progressing?
Archiblogger posing questions of a historical and contextual nature.
The roofscape of Hampstead Garden Suburb
Residents, architects and roofers need to understand detailing.
Homes, landlords. tenants and the new housing standards
What will it all mean?
The Architectural Technology podcast: Where it's AT
Catch-up on the latest episodes.
Edmundson Apprentice of the Year award 2026
Entries now open for this Electrical Contractors' Association award.
Traditional blue-grey slate from one of the oldest and largest UK slate quarries down in Cornwall.
There are plenty of sources with the potential to be redeveloped.
Change of use legislation breaths new life into buildings
A run down on Class MA of the General Permitted Development Order.
Solar generation in the historic environment
Success requires understanding each site in detail.