The HCA Red List of Endangered Crafts


Mouth blown sheet glass making


The making of sheet glass using the technique of mouth-blowing.


Status Critically endangered
Historic area of significance Sunderland
Area currently practised Birmingham
Origin in the UK 12th Century
Current no. of professionals (main income) 1
Current no. of professionals (sideline to main income)
Current no. of trainees 2
Current total no. serious amateur makers
Current total no. of leisure makers
Minimum no. of craftspeople required



The Anglo-Saxon abbot, Saint Benedict Biscop, is credited with bringing glass-making to Sunderland, and Britain, back in the 7th Century AD. The windows of Bishopwearmouth Monastery were glazed by Biscop and his team of glaziers. This tradition continued into the 20th Century and Sunderland’s glass factories produced some of the finest glass in the world. The Hartley Wood mouth-blown sheet glass factory in Sunderland was operational from 1892 to 1992 and made glass for Tiffany and cathedrals all over the world. The National Glass Centre Sunderland was set up to celebrate this local history.

The last remaining company in the UK, English Antique Glass in Birmingham, has one master craftsman and two trainees who are learning the trade.



The molten glass is gathered on the end of the blowpipe and is coloured by rolling in intensely coloured globs of glass known as frit. When the glass is the right size and shape it is gradually blown and shaped, continuously re-heating it, into a long wide bulb. Once the right shape is achieved the hot glass is cut open at both ends so that it becomes an open cylinder or tube which then has to cool and anneal. The cylinder is then cut along its length and reheated, during which it is carefully flattened out to become a sheet of coloured glass.

Most window glass in the early nineteenth century was made using the cylinder method. Unlike modern float glass, each piece is unique, with air bubbles and slight variations in design.

Handmade glass comes in a range of variations including clear, coloured, seedy, crackle (alligator skin appearance), and opal (a slightly obscuring glass).


Local forms




Allied crafts:


Issues affecting the viability of the craft

  • Market issues: Most glass is now manufactured using the float method, or mouth blown glass is imported from other countries such as Poland and Germany.
  • Training issues: There are no training routes available. English Antique Glass is training two people on the job to try to preserve the skills in the UK.
  • Technical issues: There are many technical challenges to the successful production of this material, not least the challenge of successfully annealing the glass so that it does not spontaneously shatter during or after cooling.  The carcinogenic nature of some of the minerals used to colour the glass so that it retains its colour undimmed for over a millennium is another issue, as is the cost of raw materials such as gold which has to be melted into the glass to produce the most vivid pinks.


Support organisations


Craftspeople currently known

Businesses employing two or more makers:


Other information

There is only one mouth blown sheet glass manufacturer in the UK, and there are only a handful in the world including companies in Poland and Germany.