Historic stained glass window making

The German monk, Theophilus wrote Diversarum Artium Schedula, a manual on medieval stained glass making in the twelfth century; it is one of the earliest sources of knowledge on the matter. As stained windows were a means of biblical story telling, the Reformation had an effect on the craft. With the decline in religious zeal and symbolism, glass painters lost their most important source of work, whilst this left glaziers busy replacing windows. Coloured glass does not fade but paint can be lost and glass corrodes over time, so much work currently goes into the conservation and repair of old stained glass.

Stained glass was made by mixing metallic oxides into the container in which the glass was melted. This was then blown and turned into sheets. Window designs were drawn out to scale, glass shapes were cut to size with a hot bar of iron and smoothed out with a ‘grozing iron’. The individual pieces of coloured glass were decorated and detailed with paint. Once painted, the glass was placed in the kiln, thereby melting the paint to the glass. After this, the glass was laid out over the pattern and bound together. Each differently coloured pane of glass was bound with lead strips, making a well-defined black outline. Size and weight were taken into consideration for transportation and assembled in the place of construction. Iron bars were used to support them. Changes in the style of painted glass can be seen to reflect changes in architectural styles. With the Gothic influence of the thirteenth and fourteenth centuries, painted glass became more detailed and windows larger. Yet there were technological advancements as well as cultural shifts. In around 1300, it was discovered that white glass could be stained different shades of yellow, which meant that one pane need not entirely be the same colour. This also allowed for more detailed painting. By the mid-sixteenth century colour was introduced with enamels to emulate fine art painters. English glass painters were almost entirely dependent on enamelling as the method of colouring glass (because the skills to make coloured blown sheets were partly lost) which also meant that lead strips were no longer needed to the same extent as they previously were. During the Gothic Revival the skills were rediscovered. Some crafts people today still use the heavy leaded technique for desired outcome.

The basic techniques have remained the same.

• Mouth blown sheet glass making – hand blown or ‘Antique’ glass is the standard glass used for stained glass windows. It is created by creating a glass bubble, piercing both sides making a cylinder, and then cutting the cylinder and letting it unfurl and cool flat. The glass can be made with a variety of colours and textures. This is now an extinct craft in the UK.
• Cartooning – creating a full size drawing of the window.
  Selecting and cutting the glass – glass shapes are cut to size with a hot bar of iron and smoothed out with a ‘grozing iron’.
• Painting – glass is painted using a variety of different tools and techniques, then kilned so that the paint melts to the glass.
• Leading – the glass is laid out over the pattern and bound together with lead strips, making a well-defined black outline. It can be reinforced with bars.
• Cementing – Cement is then used to secure the panel and fill any remaining gaps in the lead, adding stability and waterproofing to the joints.
  Installation

Skills in designing and cartooning for stained glass in historic buildings take time to develop and traditionally these skills are passed from master to apprentice or teacher to student over years. There are specific challenges in designing for traditional windows such as: how light interacts with the architecture; choice of lead sizes (for structure and aesthetics); the quantity and quality of paint used to filter the light; designing windows that use the shapes of the glass pieces and position of tie-bars to maximise the physical strength of a window constructed with lead, which is a metal that softens over a long period of time.

Removing and installing new and historic leaded panels in large stone windows requires specialist skills in stone and metalwork. There are a handful of studios capable of this highly specialised work.

• Loss of skills: The construction of large scale traditional painted, stained and leaded windows made with antique glass for buildings is in dangerous decline.
• Ageing practitioners: Skilled artists and craftspeople who are skilled ‘masters’ are aging and retiring with few opportunities for apprentices to learn in studios. The British Society of Master Glass Painters has 61 accredited members (Fellows and Associates). A survey amongst them completed this month with 39 respondents showed that 41% will be retiring in the next 10 years and that 10% have already retired.
• Lack of opportunities for skilled makers to pass on their skills: The survey also showed that 59% of masters (post formal education) had benefited from working in a studio or completing a formal apprenticeship. Today only 18% of the respondents are in a position to pass on their knowledge and skills. However, a further 33% indicated that they would like to offer apprenticeships if the funding was available.
• Decline in educational opportunities and courses: In the last thirty years there has been a serious decline in the number of dedicated courses for traditional stained glass at art schools and universities. There is vital outreach work to be done, as young people don’t know there is a career pathway into stained glass, and it isn’t on any education curriculums. Closure of all higher-level courses that solely focus on stained glass is a shocking fact. Even colleges and universities that offer glass courses, such as UCA in Farnham, and the University of Sunderland don’t offer traditional stained glass as an option. It has become something of a fringe activity, often being absorbed into broader studio glass and ceramics curriculums. The latest survey amongst accredited members of the Society confirmed that 67% of them had completed formal stained glass training to higher education level or other artistic training to degree level. However, 74% of respondents said that the courses that had taken them into the profession no longer exist and the remaining respondents were not sure of the status of their courses. Further research by the British Society of Master Glass Painters revealed that only Swansea College of Art is teaching a full curriculum of stained glass at higher education level. Some core skills such as taking templates, laying out a drawing for a window, designing, cartooning, painting, staining, glazing and fittings windows are rarely being taught.
• Lack of training and employment opportunities with larger companies: Established studios such as Chapel Studio and Godard & Gibbs, which used to employ and train many crafts workers, have closed.
• Relevance in today’s world: Historic buildings such as churches are financially challenged and not commissioning many new works of art. The number of commissions are a fraction of those commissioned through the Victorian era and the post-war period. New buildings don’t incorporate traditionally made windows because they don’t meet current building regulations.

• British Society of Master Glass Painters
• The Glass Society

The British Society of Master Glass Painters hosts a list of training providers.

Postgraduate and degree courses 

There are 9 post graduate and degree courses remaining in the UK for students wishing to make a career from glass. Most of these only offer stained glass as a module.

Swansea College of Art is currently the only course in the country that offers the opportunity of working with glass on an architectural scale as well as creating gallery based work. It was established in 1932 under the tutelage of Howard Martin, who also set up the only stained glass studio at that time in Wales, Celtic Studios. During the 70s, 80s and 90s Swansea was internationally renowned, attracting students from Europe, the USA, Australia and Japan.

Apprenticeships 

There are plans for a Level 4 apprenticeship scheme (approved in September 2021 but not yet operating) at the Swansea School of Art.

• The British Society of Master Glass Painters holds a list of its accredited members on its website.

This data is from a 2023 survey of Fellows & Associates of the British Society of Master Glass Painters:

39 people responded to the survey. All respondents are working at the highest professional level in the craft.

• Full time makers – 77% said it was their main income
• Part time makers – 23% said it was part of their income
• Professional experience – 93% of respondents have been working in the craft for over 20 years and 42% for over 40 years. These decades of experience mean that the respondents are well placed to comment on the changes in the craft, but this also demonstrates a risk in that just 7% have been practising for 10-20 years and none  have been practising for 50-10 years.
• Masters reaching retirement age – 41% will be retiring in the next 10 years and 10% have already retired.

Passing on skills to the next generation:

• 59% of masters (post formal education) had benefited from working in a studio or completing a formal apprenticeship. Today only 18% of the respondents are in a position to pass on their knowledge and skills. However, a further 33% indicated that they would like to offer apprenticeships if the funding was available.
• 67% of masters had completed formal stained glass training to higher education level or other artistic training to degree level. However, 74% of respondents said that the courses that had taken them into the profession no longer exist and the remaining respondents were not sure of the status of their courses.

*The making of work on all scales is threatened, but particularly the complex skills in designing and making painted and leaded stained glass windows on a large scale for architectural settings

• Capturing the Magic – The Making of Stained Glass, made by the Stained Glass Museum – stainedglassmuseum.com/resources
• Marilyn Griffiths BEd (Hons) BA (Hons) MPhil